5.1 Introduction This chapter covers internal MT1432BA memory (option) registers called S-Registers, where certain MT1432BA modem and Command mode configurations are stored. Each S-Register is assigned a number (S0, S1, S2, etc.). Use the S command to read and/or change the value stored in an S-Register (ATSr? to read and ATSr= to change S-Register values). Refer to Section 5.2, Reading and Assigning S-Register Values. S0 Number of Rings Until Modem Answers Unit: 1 ring Range: 0-255 Default: 1 Description: S0 defines the number of rings the modem waits before answering an incoming call. The default value is one ring (Decimal 1), which means that the modem answers the call immediately after the first ring. The maximum number of rings that can be configured is 255. Setting the value to zero (0) disables auto-answer completely. S1 Rings Which Have Occurred Unit: 1 ring Range: 0-255 Default: 0 Description: S1 counts the number of rings that have occurred. It is a "read" type of register and is seldom, if ever, used in typical operation. Each time an incoming ring signal is detected, S1 increases its value by one, up to a maximum of 255. If you set S1 to a value other than its default value of zero, or if the value is increasing with rings, this new value remains stored in S1 for eight seconds after the last ring is counted, after which time the value reverts to zero. S2 Escape Code Character Unit: ASCII Character Range: 0-127 Default: 43 (+ sign) Description: S2 defines the escape code character. The default character is the plus (+) sign (Decimal 43). It may be set for any ASCII character. Setting an S2 value greater than 127 results in no escape character, and therefore no means of entering Command mode from On-line mode without breaking the on-line connection. S3 Return Character Unit: ASCII Character Range: 0-127 Default: 13 Description: S3 defines the character recognized as Carriage Return (RETURN) or "Enter". The default setting is CTRL-M (Decimal 13), which is the ASCII code for the RETURN key on most keyboards. S3 may be set for any ASCII character. S4 Line Feed Character Unit: ASCII Character Range: 0-127 Default: 10 Description: S4 defines the character recognized as Line Feed. The default setting is CTRL-J (Decimal 10), which is the ASCII code for the Line Feed key on most keyboards. S4 may be set for any ASCII character. S5 Backspace Character Unit: ASCII Character Range: 0-127 Default: 8 Description: S5 defines the character recognized as BACKSPACE. The default setting is CTRL-H (Decimal 8), which is the BACKSPACE key on most keyboards. S5 may be set for any ASCII character. S6 Wait Time for Dial Tone Unit: 1 sec. Range: 2-255, 4-255** Default: 2, 4** Description: S6 sets the time the modem waits after the RETURN key is pressed before executing a dial command. The default setting is two seconds (Decimal 2) or four** seconds. S7 Time for Carrier (Abort Timer) Unit: 1 sec. Range: 1-255, 1-45* Default: 45 Description: S7 defines the Abort Timer (lack of carrier) delay time. The default value is 45 seconds (Decimal 45). This means that, after dialing, the modem waits for a carrier signal for up to 45 seconds and, if none is detected, aborts the call. The maximum S7 value is 255 (or 45*) seconds. S8 Pause Time for Comma Unit: 1 sec. Range: 0-255, 4-255** Default: 2, 4** Description: S8 sets the length of the pause caused by a comma inserted in a dialing command. The default setting is two seconds, (or two units Decimal 2) or four** seconds, where each unit is one second. S8 may be set for up to 255 seconds. S8 also sets the time the modem waits before retrying a call after detecting a busy signal. Some computer systems need more than two seconds to reset (in which case you should increase the value of S8). S9 Carrier Detect Response Time Unit: 100 mSec. Range: 1-255 Default: 6 Description: S9 sets the time delay between when the modem first detects a valid incoming carrier signal and when the modem turns on its Carrier Detect circuit. The default setting is 600 milli- seconds, or six units of 100 mSec each (Decimal 6). S9 may be set for up to 25.5 seconds. S10 Carrier Loss Disconnect Delay Time Unit: 100 mSec. Range: 0-255 Default: 7 Description: S10 sets the time a carrier signal must be lost before the modem disconnects. The default setting is 700 mSec, or seven units (Decimal 7) of 100 mSec. Maximum delay is 25.4 seconds (Decimal 254). Setting the S10 value to 255 causes the modem to not disconnect with loss of carrier. (This S-Register is limited to 2400 bps operation.) S11 Tone Dialing: Tone Spacing and Duration Unit: 1 mSec. Range: 1-255, 80-255* Default: 70, 80* Description: S11 sets the speed of tone dialing (spacing and tone duration times). The default value is 70 units (Decimal 7) or 80* units, where each unit is one mSec, meaning that each tone is on for 70 mSec with a 70 mSec pause between each. The minimum S11 value allowed by most telephone systems is 50 mSec (50 units). Very few telephone systems can handle anything faster than that. The maximum S11 value is 255 mSec (255 units). S13 Remote Configuration Escape Character Unit: ASCII Character Range: 0-127 Default: 37 (% sign) Description: S13 defines the remote configuration escape character (which becomes your modem's remote configuration character). The default is three percent symbols (%%%). When the S13 character is entered three consecutive times from a remotely connected site, your modem responds with its Remote Configuration procedure. S15 Callback Time Delay Unit: Sec Range: 10-255 Default: 20 Description: S15 defines the time delay between Callback attempts after initial passwords have exchanged between modems. S16 Callback Attempts Unit: 1 Attempt Range: 1-255 Default: 4 Description: S16 defines Callback attempts after initial passwords have exchanged between modems. S17 Changing Break Time Unit: 10 mSec. Range: 0-2.5 sec Default: 250 Description: S17 defines the length of break time (space) sent to local PC. Depending on the host computer, you may need to send a "break" signal to commence or interrupt a session. The default is set for a 25 to 250 mSec break. The break time is changed in 10 mSec increments by increasing or decreasing the value of S17. S24 PBX/CBX Disconnect Drop Time for DSR/CTS/CD Unit: 50 mSec. Range: 0-255 Default: 20 Description: Some PBX and CBX phone systems require the modem's DSR, CTS, and/or CD signals to behave in a certain manner when calls are disconnected. The MT1432BA's &R, &S, and &C commands cause the modem to drop these signals for a specified time period upon disconnect, and then bring the signal(s) up again. S24 defines the length of time that the signal(s) drop. The default setting of 20 results in a one second drop time, which is what most PBX/CBX systems with this requirement need. S25 DTR Dropout Time Unit: 100 mSec. Range: 0, 1 through 255 Default: 0 Description: S25 defines the amount of time that DTR must be dropped before the modem disconnects. Normally, a disconnect occurs when DTR is dropped for 50 milliseconds or more. This dropout time can be increased, up to a maximum of 25.5 seconds. The S25 unit value for zero is the default value of 50 mSec. For values from 1 through 255, the unit value is 100 mSec. S26 Failed Password Attempts Unit: 1 failed attempt Range: 0-255 Default: 0 Description: S26 counts the number of times a failed password attempt occurs. For example, if you entered ATS26? the message 003 would be displayed, meaning someone has failed three times to gain access to your modem using its password security system. S29 Local Inactivity Timer Unit: minutes Range: 1-255 Default: 20 Description: S29 defines the amount of idle time that can elapse between AT commands after the SETUP password has been entered. If this timer expires, the LOGIN and SETUP passwords will have to be re-entered. S29 only takes effect when the modem has been sent a #DB1 command, which secures the modem from local and remote configuration or dialing (i.e., no AT commands can be sent until the LOGIN and SETUP passwords have been entered). S30 Inactivity Timer Unit: 1 min. Range: 0-255 Default: 0 Description: S30 causes the modem to disconnect if no data is transmitted or received for a specified time. This timer runs during both Reliable and Normal connections. The timer restarts any time a data character is passed through the serial port (either sent or received). If noise on the phone line causes an error to be received during Normal mode, this also restarts the timer. The default value is off (0). The inactivity timer is disabled by setting S30 to 0, which is the factory default setting. S32 Time Elapse for Escape Sequence Unit: 1 second Range: 0-255 Default: 20 Description: S32 sets the time period to validate the escape sequence. If the time interval expires before the escape sequence is employed (by hitting RETURN), the escape sequence is aborted. The default is 20 units (one second). S34 Buffer Length of Command Mode...After On-line Escape Sequence Unit: ASCII Character Range: 0-60 Default: 10 Description: If the number of characters after AT exceeds the S34 buffer length value, the buffer is cleared and the escape sequence is aborted. S36 Time Between DTR Inactive and Modem Off-Hook Unit: 1 Second Range: 0-255 seconds Default: 0 Description: The DTR Busy-out feature uses S-Register S36 to set the time between DTR inactive (low) and the modem going off-hook. S36 can be set in one- second intervals from 0 to 255 seconds. With the default setting of S36=0, DTR Busy-Out is disabled (i.e., DTR won't Busy-Out). S37 Time Between DTR Active and Modem On-Hook Unit: 1 Second Range: 0-255 seconds Default: 5 Description: S37 sets the time between DTR being active and the modem going on-hook (not busy). S37 will only function in conjunction with S36. 5.2 Reading and Assigning S-Register Values The S command is used to assign a value to, and to read the current value of, an S-Register. To read an S- Register value, enter the letter S followed by the S-register number and a question mark (?), then hit RETURN. For example, entering ATS7? and hitting RETURN displays the value of S-Register S7 in a 3- digit decimal form. The number 8 would appear as 008, the number 30 would appear as 030, and the number 255 would appear as 255. To assign a value to an S-Register, enter the letter S followed by the S-Register number and an equals sign (=), and then a decimal response to the message "ENTER THE NEW VALUE IN DECIMAL FORMAT". Convert all ASCII characters to their decimal equivalents before entering them. S-Register decimal values range from 0-127 for ASCII characters, or 0-255 for numeric values. A complete ASCII conversion chart is located in Appendix A of this manual. 5.2.1 Examples of Assigning Values 1. Let's say you wish to have longer pauses caused by the comma in a dial command; five seconds instead of two. Entering ATS8=5 assigns 5 as the value for S-Register S8 (meaning the modem pauses five seconds for a comma in a dial command). 2. In a second example, let's say that you wish to configure the MT1432BA modem to answer incoming calls after the 30th ring instead of after the first ring. To configure S-Register S0 with a value of 30, enter ATS0=30 and hit RETURN. 3. In a third example, let's say you are calling long distance to another country code, and it is taking a long time to connect. The S-Register S7 (Abort Timer) setting of 35 seconds you have stored in non-volatile memory, is insufficient. The abort timer times out and cancels the call before a connection is made. To change the S7 value to 45 seconds, enter Command mode, then enter ATS7=45 and hit RETURN. Now, after dialing, the modem allows 10 more seconds for a carrier signal before aborting the call. The additional 10 seconds should provide enough time for international calls. 5.2.2 Examples of Reading Values To verify that you entered the value correctly in the above examples, enter ATS8? and hit RETURN in the first example, ATS0? in the second, and ATS2? in the third example. You should receive the response 005 in the first example, 030 in the second example, and 045 in the third example. When configuring the S-Registers, it is a good practice to include the verification read-entry in the same command line as the configuration assignment-entry. In the three preceding examples, enter ATS8=5S8?, ATS0=30S3?, and ATS7=45S7?. 5.3 AT Command and S-Register Summary Your MT1432BA has a default configuration of originating a call to another 14400 bps modem that supports error correction, data compression and flow control ("Maximum Throughput"). If the receiving modem is not compatible, the MT1432BA can match protocols, provided the protocols are industry standard (i.e., CCITT or Bell ) and not proprietary. You may, however, have an application where you do not want or require this kind of maximum throughput (e.g., service does not support error correction, or the V.42 handshake interferes with logon sequence). You may want to configure the MT1432BA to be strictly an auto-answering device or perhaps function in a Unix environment. The &W command, used in conjunction with specific other AT Commands and S-Registers, can reconfigure the MT1432BA to conform to a specific application. An example of the &W command: AT&E2$SP1#L3$R0$MB14400$SB57600$EB1S0=10&W0 The MT1432BA can store its configuration parameters and S-Register values in its non-volatile memory. The command AT&W0 (or AT&W) causes the modem to store its current parameters and values in its non- volatile RAM. This command also sets the modem so that on power up, or when it is reset with an ATZ command, the modem reads all its configuration and S-Register parameters from RAM, and not from the factory settings in ROM. The &W command changes the configuration parameters stored in RAM that you specifically intend to alter. All other default parameters remain unchanged. The AT&W1 command sets the modem so that it does not store its parameters to RAM, and on power up or when an ATZ command is entered, parameters will be read from the factory default settings in ROM. Before using the &W command, you may want to view the modem's current operating parameters. Use the ATL5, ATL6 and ATL7 commands to display the current modem configuration. 5.3.1 Summary V.42 error correction is built into the MT1432BA to detect and correct virtually 100% of transmission errors, (usually caused by noisy phone lines). When errors are detected, the V.42 protocol causes the modem to retransmit the data block in which the error was found. V.42bis and MNP 5 data compression features are built into the MT1432BA to provide a higher data throughput than the modem's modulation speed. The throughput increase depends on the type of data being transmitted. The MT1432BA also supports CCITT V.17 Group 3/EIA TR-29 Class 2 fax operation. This enables the modem to send and receive text, graphics and images to and from any Group 3 fax machine. The MT1432BA can be set for one of three different modes of operation, along with activating data compression in the reliable mode. The Normal Mode (&E0) disables error correction, the Reliable Mode (&E2) turns it ON, and the Auto-Reliable Mode (&E1) allows the modem to automatically turn V.42 ON when it detects its use in another modem. Flow control methods are used by the MT1432BA to prevent data loss from buffer overflow. The modem can both initiate flow control and respond to pacing, using either Xon/Xoff commands or RS232C signaling via CTS (from the modem) or RTS (from the computer/terminal). Hewlett- Packard ENQ/ACK is also supported. If needed, Xon/Xoff commands can be passed through the modem to a remote computer or terminal. The MT1432BA's speed conversion feature allows the modem to operate at one speed over the telephone lines and another speed over the RS232C serial port. This allows the computer or terminal to communicate with the modem at a fixed speed of up to 57,600 bps, while the modem operates at various rates of up to 14400 bps (V.32bis enabled). This ability is vital if data compression is to be effective, since your computer or terminal must send data to the modem at a higher speed than the rate at which the modem is sending data over the phone line. 6.1 Introduction This chapter describes how the MT1432BA Callback and Remote Configuration features operate. These features use a multi-level security system, which involves the use of LOGIN Passwords, Set-up Passwords and Remote Escape Characters. The primary level security code is the modem's LOGIN Password. Once this password is entered, other passwords can be used. For instance, entering the LOGIN Password will allow you to enter the Set-up Password, which, in turn, allows you to enter Callback Passwords and dial back phone numbers. Callback Passwords tell your modem what dial back phone number to call. The Remote Escape Character is the key to using the Remote Configuration feature. The Remote Escape Character lets you enter Command mode via a remote call, so that you can enter AT commands just as if you were locally connected. You must also enter your modem's Set-up Password . The Remote Escape Character is contained in S-Register S13. 6.2 Callback Feature Description The Callback feature protects your network from unauthorized access and helps control long distance costs. By use of Callback Passwords and dial back phone numbers, you can have your modem "dial back" remote locations immediately after being called. A special command (Enable Callback #DB) turns your modem into a Callback security modem. The Callback Password/Phone number entry is protected by two-level security (your modem's LOGIN Password and Set-Up Password) that keeps unauthorized personnel from changing parameters. When you first get your modem, you need to change both security level codes to your unique settings. The Callback Passwords and dialback phone numbers are in a special Callback Password/dial back phone number memory (30 numbers long). You use the modem's LOGIN Password and the Set-Up Password plus special Callback commands to access this memory. The memory is thirty numbers long and replaces your modem's normal phone number memory. Each number is 35 characters long and can contain commands as well as phone numbers. You need to set up your modem with the numbers and codes as part of the dialback initilization procedures. Your modem will also remember if the incoming call was reliable or not, and make the call back accordingly. 6.3 Remote Configuration Description The Remote Configuration feature is a network management tool that allows you to configure modems remotely. This means you could configure modems anywhere in your network from one location without having to visit the sites or rely on remote users to follow your instructions. With Remote Configuration, which is protected by two level security, you can downline load new parameters, program new V.42 capabilities and implement new features. Remote Configuration also makes troubleshooting a remote location a lot easier. The way Remote Configuration works is that S-Register S13 has been set-up to contain the special Remote Configuration escape code. When calling a Remote Configuration equipped modem, you enter the proper Remote Escape code to enable entering your Set-up Password. After entering it, you can then execute AT commands as if you were connected locally. If you set S-Register S13 to zero, Remote Configuration is disabled. 6.3.1 Initial Set-up Procedures for Callback/Remote Configuration. Your modem was shipped with a default LOGIN Password and Set-up Password (LOGIN=MULTI-TECH and Set-up=MODEMSETUP) so that you have access to the features used for configuring the modem. Because the defaults are in the modem owner's manual, and anyone can find out what they are, you should change the codes as the first step of your initialization procedure. TABLE 6-1. Modem LOGIN, Set-up and Remote Escape Code Procedures Step Procedure To change your modem's LOGIN Password and Set-up Password: Note: Passwords are upper/lower case sensitive. The case you enter here is the case that must be used at Log-In. 1. Type AT#IMULTI-TECH and hit Return. Your modem will respond with: OK (if the LOGIN Password is wrong, the modem's response is ERROR) 2. Type AT#SMODEMSETUP and hit Return. Your modem will respond with the following: OK (or ERROR if wrong Set-up Password) Note: At this point you can change the LOGIN Pass word and Set-up Password. Step Procedure 3. Type AT#I=xxxxxxxxxx (with any keyboard charac ters used, minimum 6 maximum 10) and hit Re- turn. Your modem responds with: OK 4. Type AT#S=yyyyyyyyyy (with keyboard characters used, minimum 6 maximum 10) and hit Return. Your modem responds with: OK To change your Remote Configuration feature status: 5. If you want Remote Configuration off, set S-Register S13 to 0 (zero). Refer to Chapter 5 for details on how to set S-Register values. 6. If you want Remote Configuration on and wish to change the Remote Escape Character, change the S-Register S13 value. If you leave it at the default value, decimal 37 (% sign) will be your modem's remote escape character. To turn your modem's Callback Security feature on and off: 7. If you want Callback Security with both remote and local password security, enter AT#DB1 and hit RETURN. You must turn on Callback Security to be able to enter dialback phone numbers. 8. If you want Callback Security on with just remote password security, enter AT#DB2 and hit RETURN. You must turn on Callback Security to be able to enter dial back phone numbers. If you want to use your modem to call another modem that is also set for Callback, you must enter AT#DB3 before you dial. (Note: this is for your modem if you are set for #DB1 or #DB2.) Once you have disconnected from that call, your modem will go back to its original setting. 9. If you want Callback Security turned off, type AT#DB0 and hit RETURN. To set parity of the password/message prompt: 10. The parity default value for your modem is no parity (AT#P0). If your modem's prompt messages use even parity, enter AT#P2 and hit RETURN. For odd parity,enter AT#P1 and hit RETURN. 11. Enter the &W0 command and hit RETURN to store parameters and S-Register values in RAM. TABLE 6-2. Callback Password and Dial Back Phone Number Entry Procedures Step Procedure 1. Enter your modem's LOGIN Password (as selected in Table 6-1) by entering the following: AT#Ixxxxxxxxxx (xxxxxxxxxx from Table 6-1) Enter your modem's set-up Password (as selected in Table 6-1) by entering the following. AT#Syyyyyyyyyy(yyyyyyyyyy from Table 6-1) 2. Enable the Callback Security feature by entering the following: AT#DB2 or AT#DB1 The following message is displayed on your monitor: Entering Callback Mode, current phone numbers will be erased. Do you want to continue? Y/N 3. Enter a Y or N and hit RETURN. Note: If this is your first time into Callback Mode, we recommend answering Y to clear all previous Call back Passwords and phone numbers from memory. TABLE 6-2. Callback Password and Dial Back Phone Number Entry Procedures (Cont'd) Step Procedure 4. Enter individual Callback Passwords for each of 30 different phone number memory locations as follows: AT#CBN0xxxxxxxxxx To enter Call back Password for the first location (a minimum 6 characters, up to a maximum of 10 characters must be used). AT#CBN1xxxxxxxxxx To enter Call back Password for the second location...etc (a minimum 6 characters, up to a maximum of 10 characters must be used). Note: The first character of your first Callback Password must be non-numeric. 5. Enter individual phone numbers for each of the 30 memory locations as follows: AT+ - DP...????N0 (number for location N0) AT+ - DT...????N1 (number for location N1)...etc Note:You must indicate within the command string that the modem either Pulse dial (ATDP...) or Tone dial ATDT...). The maximum length of the number is 35 characters. The number may include commands as well as your number, so as to create macro-type command numbers. The + and/or - characters entered before the phone number are optional. The + (Deposit Number) code allows a caller to enter the number he or she wishes the Callback modem to call back when the caller uses a particular password (Step 3 of Table 6-3). The - character enables direct entry when the caller uses that correct password (Step 3 of Table 6-3) without the Callback modem having to return the call. The ??? entry at the end of the phone number is optional and indicates a subcode number to the main phone number for that location. The ??? used to dial different extensions at the same basic number. To use this optional feature, enter the number of ? marks where indicated equal to the number of digits in the desired extension number (i.e., with a 4 digit extension enter ????). When a caller uses that particular password (Step 3 of Table 6-3), he or she then enters an extension number directly after the password, with the same number of digits as the number of ? marks originally entered. When calling back that particular number, your modem will also dial the indicated extension number. Note: To view Callback Passwords/Numbers, use the L Command. Entry Procedures (Cont'd) Step Procedure 6. To store changed parameters to memory, enter AT&W0 and hit RETURN. Note: If you have enabled Callback Security (#DB1 in step 2 of Table 6-2), the MT1432BA will be secured locally. To gain local access, you must again perform steps 7 and 8. 7. Enter your modem's LOGIN Password (as selected in Table 6-1) by entering: AT#Ixxxxxxxxxx (xxxxxxxxxx from Table 6-1) 8. Enter your modem's Set-up Password (as selected in Table 6-1) by entering: AT#Syyyyyyyyyy (yyyyyyyyyy from Table 6-1) TABLE 6-3. Callback Operational Sequence Procedures Step Procedure Perform the following steps when dialing into a dialback modem. 1. When called, the modem answers and after a slight delay, responds with: Password> 2. Enter your modem's LOGIN Password (Table 1) and hit RETURN. If entered correctly, the modem responds with: DB> 3. Enter the Callback Password corresponding to the phone number you wish called back and hit RE- TURN (Callback Passwords and phone numbers entered in Table 6-2). You can also use special characters + and -. They must have been entered as part of the Callback phone numbers in Step 5 of Table 6- 2. If you use the - character along with your password, the Callback modem will connect directly without hanging-up and calling back. If you use the + character along with your password, you can also enter a phone number which you wish the Callback modem to dial after hanging-up. The + and - charac- ters must be entered after the Dial-back password, (i.e., DB>xxxxxx+). This is also the point where you enter an extension number if your Callback number used the ??? feature (Step 5 in Table 6-2). You have three tries at each prompt to enter the information properly, with an incorrect entry resulting in a password retry. You must enter the requested information correctly within one minute or the Callback modem will hang-up. When the information is entered properly, the called modem will hang-up and after a 15 second delay, call you back. When your modem answers, the dialback modem will respond with the following: Password> 4. Enter the modem's LOGIN Password again (the same as in Step 1). The Callback modem responds with: CONNECT You are now in Data Mode. 6.3.2 Remote Configuration Procedures The procedures for using the Remote Configuration features are the same whether or not a call originates from the remote modem. Once the modem is on-line, perform the procedures in Table 6-4. TABLE 6-4 Remote Configuration Operation Procedures Step Procedure 1. Remote Escape Configuration requires a BREAK, then three % signs to be sent if the default value in S-Register S13 has not been changed. The modem responds with: 1. - DATA Mode 2. - COMMAND Mode Step Procedure 2. You then select 1 or 2 . With 1, the modem goes back into data mode and with 2, the modem re sponds with the following: Password> 3. Enter your Set-up Password, and if the code is correct the modem responds with: OK You can now use any AT commands of the modem being remotely configured as if they were being entered locally. You cannot change the Set-up of the LOGIN Password until you enter the proper LOGIN Password. 4. When you are done entering AT commands and you want to exit, type AT0 and hit return. The modem responds with: 1. DATA Mode 2. COMMAND Mode 5. Enter a 1 to go back on-line with your computer, or enter 2 and the correct password to talk to your modem. 6.4 Remote Configuration and Callback Security AT Commands The following AT commands are used with Remote Configuration and Callback Security features. Assign Passwords When you have callback security enabled for for Callback Phone the MT1432BA, anyone trying to connect with Numbers the modem will be required to furnish a password. The #CBN command allows you #CBN to enter passwords for each of the 30 memory locations used for callback security. The length of each password can be up to 10 characters, but must be at least 6 characters. Any ASCII character can be used. The format for this command is AT#CBNyyxxxxxxxx with xxxxxxxx representing the password and yy being the memory location (0-29). Each callback password (xxxxxxxx) must start with a non-numeric character. Callback Security The purpose of this command is to enable Enable/Disable or disable (default setting) your modem's callback security option. Once this command is executed, #DB you modem will undergo some significant changes. For example, the phone number memory locations (N0 through N9) will be used for passwords and phone numbers. In other words, you will not be able to dial from memory or use the DTR dialing feature. You can turn on callback security by typing AT#DB1 or AT#DB2 and pressing . If you want to engage both remote and local password security, use the #DB1 command. This sets up the modem so you have to provide passwords to dial into the modem and to dial out. For remote password security only, use the #DB2 command. This allows the local operator to dial out without providing the LOGIN and SETUP passwords. Use #DB3 when calling another modem with callback security active. Change LOGIN The default LOGIN password for your Password MT1432BA is "MULTI-TECH". If you choose to activate callback security, you should #I change the LOGIN password using this command in the following format: AT#Ixxxxxxxxxx (where xxxxxxxxxxxxxxxx is the current LOGIN password). Your modem will respond with "OK", indicating that you can enter the new LOGIN password as follows: AT#I=yyyyyyyyyy You can select any combination of keyboard characters (upper/lower case sensitivie) between six and ten characters long. Change SETUP The default SETUP password for your Password MT1432BA is "MODEMSETUP". If you choose to activate callback security, you #S should change the SETUP password using this command in the following format: AT#Stttttttttt (where tttttttttt is the current SETUP password). Your modem will respond with "OK", indicating that you can enter the new SETUP password as follows: AT#s=uuuuuuuuuu You can select any combination of keyboard characters (upper/lower case sensitivie) between six and ten characters long. Erase Callback This command erases the single callback Password password specified by xx (0 through 29). #RCBNxx Erase Callback This command erases the single phone Phone Number number specified by xx (0 through 29). #RDNxx 6.5 Remote Configuration and Callback Security S-Registers The following S-Registers are used with Remote Configuration and Callback Security features. S13 Remote Configuration Escape Character Unit: ASCII Character Range: 0-127 Default: 37 (% sign) Description: S13 defines the remote configuration escape character (which becomes your modem's remote configuration character). The default is three percent symbols (%%%). When the S13 character is entered three consecutive times from a remotely connected site, your modem responds with its Remote Configuration procedure. S15 Callback Time Delay Unit: Sec Range: 10-255 Default: 20 Description: S15 defines the time delay between Callback attempts after initial passwords have exchanged between modems. S16 Callback Attempts Unit: 1 Attempt Range: 1-255 Default: 4 Description: S16 defines Callback attempts after initial passwords have exchanged between modems. S26 Failed Password Attempts Unit: 1 failed attempt Range: 0-255 Default: 0 Description: S26 counts the number of times there has been a failed password attempt. For example, if you entered ATS26? the message 003 would be displayed, meaning someone has failed three times to gain access to your modem using its password security system. S29 Local Inactivity Timer Unit: minutes Range: 1-255 Default: 20 Description: S29 defines the amount of idle time that can elapse between AT commands after the SETUP password has been entered. If this timer expires, the LOGIN and SETUP passwords will have to be re-entered. S29 only takes effect when the modem has been sent a #DB1 command, which secures the modem from local and remote configuration or dialing (i.e., no AT commands can be sent until the LOGIN and SETUP passwords have been entered). 7.1 Introduction Each time you power up the MT1432BA, it performs an automatic self- test to ensure proper operation. The MT1432BA also has three diagnostic test features: Local Analog Loopback, Digital Loopback (remote/automatic) and Digital Loopback (local/manual). A loopback test involves entering data from your PC and looping that data through the circuits of your modem and/or a remote modem. When the loop has been completed, the original data entered should match the data received back on your PCs monitor after the test. The Local Analog Loopback Test allows you to verify that the modem's transmitter and receiver circuits are functioning properly. The Digital Loopback Test (local/manual) allows you to verify that the remote computer or terminal, the remote modem, serial ports, the telephone line and the local modem are functioning properly. The Digital Loopback Test (remote/automatic) allows you to verify that the local computer or terminal, the two modems and the transmission line between them are functioning properly. In asynchronous mode, upon completion of testing, enter either Escape Sequence, +++AT or AT. Note: All loopback tests will operate at all speeds except 300 bps. 7.2 Local Analog Loopback Test/V.54 Loop 3 In this test, data from your computer or terminal is sent to your modem's transmitter, converted into analog form, looped back to the receiver, converted into digital form and then received back at your monitor for verification. No connection to the phone line is required. See Figure 7-1. Figure 7-1. Local Analog Loopback Test The test procedure is as follows: 1. Connect the modem to your computer. With your communication software, set the desired baud rate. 2. Type ATU0 (or ATU) and hit ENTER. This places your modem in Analog Loopback mode, in the Originate mode. The modem is now out of the Command mode and in a pseudo On-Line mode. 3. Once you receive a connect message (if responses are enabled), enter data from your keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros. 4. For a more complete test, you should also test the modem in Answer mode. To do this, you must "escape" from Originate mode by entering an Escape Sequence (+++AT or AT) . Then type ATU1 and hit ENTER to place the modem in Analog Loopback mode, in the Answer mode. Then repeat step 3. 5. When testing is completed, you may exit Answer mode by entering an Escape Sequence (+++AT or AT), which returns the modem to Command mode. 6. Your modem passes this test if the data entered from your keyboard is the same as the data received on your monitor. If different data is appearing on your monitor, your modem is probably causing the problem, although it could also be your computer. If your modem passes this test, but you are receiving errors while On-line, the remote modem or the phone line could be at fault. 7.3 Digital Loopback Test/V.54 Loop 2 (Local/ Manual) In this test, your modem must be On-Line with another modem that can respond to a request for Digital Loopback, such as another MT1432BA. The Digital Loopback Test is an on-line test that loops data sent from one modem across the phone line to another modem, then back to the first modem. See Figure 7-2. There are two ways to put a modem into Digital Loopback mode. 1. Locally or Manually, described here in section 7.3. 2. Remotely or Automatically, see section 7.4. Note: The Digital Loopback Tests can only be used with the modem in Normal mode (error correction off). In this test the local modem is placed in Digital Loopback mode. Data is entered and transmitted from the remote modem (which is not in digital loopback mode), sent across the phone line to the local modem and looped back to the remote modem. The test procedure is as follows: 1. Go into Terminal mode. Type AT and hit ENTER; you should get an OK message. 2. Dial the remote modem by entering the Dial command and the phone number, to establish On-line mode. 3. Type the Escape Sequence (+++AT or AT) which brings your modem into Command mode, while still maintaining the pseudo On-line mode with the remote modem. 4. Type ATU3 from the local PC and hit ENTER. Once you receive an OK message from your modem (if responses are enabled), the local modem is placed in Digital Loopback mode. 5. Data is typed from the remote keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros. The data received by the local modem will enter its analog receiver, be converted to digital data, be reconverted into analog, and then looped through its transmitter back to the remote modem. Your modem passes this test if the data entered from the remote keyboard is the same as the data received on the remote monitor. 6. When testing is complete, you may end the test by typing an Escape Sequence (+++AT or AT) to bring your modem into Command mode. The modem should respond with an OK message. If you wish to stay On-line with the remote modem for normal data transmission, type AT0 and hit ENTER. If you wish to terminate the call, type ATH and hit ENTER to hang up. 7.4 Digital Loopback Test/V.54 Loop 2(Remote/Automatic) In this test, your modem must be On-line with another modem set up to respond to a request for Digital Loopback, such as another MT1432BA. With the MT1432BA, this ability to respond is controlled by the &T command. AT&T4 enables the response to Digital Loopback Test (remote/automatic). AT&T5 disables the response. The modem defaults to disable on power up, so this must be changed on the remote modem before the modem will respond to a request for the Digital Loopback Test (remote/automatic). Initiate the Digital Loopback Test (remote/automatic) with the ATU2 command which automatically places the remote modem in digital loopback mode. Data from your computer or terminal are transmitted through your modem, and over the phone line to the remote modem, where they are then looped back to your modem. See Figure 7-3. The test procedure is as follows: 1. Go into Terminal mode. Type AT and hit ENTER; you should get an OK message. 2. Dial the remote modem by entering the Dial command and the phone number, to establish On-line mode. Note: The &T4 command must be set on the remote modem to run this test. 3. Type the Escape Sequence (+++AT or AT) which brings your modem into Command mode, while still maintaining the connection with the remote modem. 4. Type ATU2 and hit ENTER. The local modem responds to this command by transmitting an unscrambled marking signal, which causes the remote modem to place itself in Digital Loopback mode. Then the local modem exits Command mode and enters pseudo On-line mode. 5. Type data from your keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros. The data received by the remote modem will enter its analog receiver, be converted to digital data, be reconverted into analog, and then looped through its transmitter back to the local modem. Your modem passes this test if the data entered from the local keyboard is the same as the data received on your monitor. 7.5 Synchronous Mode Testing The following tests must be run with your modem in Synchronous mode (DIP Switch #12 in the Up (OPEN) position), DIP Switch #9 controls the modem's Synchronous mode testing function. (Refer to Chapter 8 for DIP Switch information.) The test procedures for Synchronous mode are different from those for Asynchronous mode. In Synchronous mode, you cannot access the modem's AT commands. With DIP Switch #9, you can perform either the Digital Loopback Test (remote/automatic) or the Digital Loopback Test (local/manual) in Synchronous mode, as described in the following sections. There is also a Local Analog Loopback Test, documented in section 7.6. 7.6 Local Analog Loopback Test (Synchronous Mode) This test diagnoses the connection between your MT1432BA and your computer or terminal. In Local Analog Loopback Test mode, data entered at the local computer or terminal are sent through the local modem's transmit and receive circuits (much like entering an ATU or ATU1 command in Asynchronous mode). You then compare the test characters (multiple upper case "U" characters in Figure 7-4) on your monitor with the characters you typed. If the characters don't match, check your computer's COM port setting, then verify your communication software's configuration. To initiate the Local Analog Loopback Test, with the modem in Synchronous mode: 1. Enter AT&M1U. This first switches your modem form asynchronous to synchronous mode, and places it into the Analog Loopback/Originate mode. The modem is now out of the Command mode and in the pseudo On-Line mode. 2. Once you receive a connect message (if responses are enabled), enter data from your keyboard. For this test, typing multiple upper case "U" characters is a good way to send an alternating test pattern of ones and zeros. 3. For a more complete test, you should also test the modem in Answer mode. To do this, Type the Escape Sequence (+++AT or AT) which brings your modem into Command mode, while still maintaining the connection. Then type AT&M1U1 and hit ENTER to place the modem in Analog Loopback mode, in the Answer mode. Then repeat step 2. 7.7 Digital Loopback Test (Local/Manual)(Synchronous Mode) This test must be run when you have a data connection with another modem. If a Local Analog Loopback Test resulted in errors, and this test passes without errors, then the problem exists in your computer-to- modem connection. In Digital Loopback Test (local/manual) mode, data passed from the remote modem's transmit circuit are looped back from the local modem and are received at the remote modem's receive circuit (multiple upper case "U" characters in Figure 7-5). First make certain that you are set up for Synchronous operation by placing DIP-Switch #12 in the UP position. To initiate the Digital Loopback Test (local/manual), DIP-Switch #9 must be in the UP position, and the Answer/Orignate switch (front of the modem) must be toggled to the UP position. Once you receive an OK message from your modem (if responses are enabled), the local modem is placed in Digital Loopback mode. To exit the Digital Loopback Test (local/manual), toggle the Answ/Orig switch to the Answer position. 7.8 Digital Loopback Test (Remote/Automatic) (Synchronous Mode) This test must be run when you have a data connection with another modem. In this test, data is passed to the remote modem and is looped back to the local modem (as if an ATU2 command was issued in Asynchronous test mode), as shown in Figure 7-6. This lets you test the local and remote modem's transmit and receive circuits, as well as your computer's serial COM port and the phone lines. If the test results in a mismatch of entered/received data (multiple upper case "U" characters in Figure 7-6), the Local Analog Loopback Test should be performed on both the remote and local modems. If that test is successful, the problem may be the phone lines. First make certain that you are set up for Synchronous operation by placing DIP-Switch #12 in the UP position. To initiate the Digital Loopback Test (remote/automatic), DIP-Switch #9 must be in the DOWN position, and the Answer/Orignate switch (front of the modem) must be toggled to the UP position. Once you receive an OK message from your modem (if responses are enabled), the local modem is placed in Digital Loopback mode. To exit the Digital Loopback Test \(remote/automatic), toggle the front panel Answ/Orig switch to the Answer position. 8.1 Introduction There are several DIP-Switch options and jumper plugs on the MT1432BA's printed circuit board. The DIP-Switches are accessible through a cutout on the side of the modem. It is unlikely you will need to access the jumper plugs, but if you do, you must remove the modem's printed circuit board from the modem's chassis. To remove the PC board from the modem enclosure, remove the retaining screw (on the bottom of the modem near the RS232 connector), and slide the PC board out of the modem enclosure. Figure 8-1. MT1432BA PC Board 8.2 DIP-Switch Option Settings Switch #1 Forced DTR -- "DTR" (Asynchronous/Synchronous Mode/Leased Line/Dial-Up) The MT1432BA must have a high DTR signal in order to operate. DTR is provided to the modem by the terminal or computer to which it is attached, through pin 20 of the RS232C/V.24 interface. If your terminal or computer is not providing DTR to the modem, you can force the DTR signal high with DIP-Switch #1. DTR function normally = Switch #1 UP DTR forced On = Switch #1 DOWN (Factory Default Setting = UP) Switch #2 Flow Control - &E4/&E5 (Asynchronous Mode/Leased Line/Dial-Up) With Hardware Flow Control, the modem uses its RS232C/V.24 interface to control the flow of data from the computer or terminal to which it is attached. CTS signal on Pin 5 of the RS232C/V.24 is brought low to stop the flow of data, and is brought high to restart it. Place DIP- Switch #2 in the UP position to enable Hardware Flow Control (&E4). Xon/Xoff Flow Control (&E5) is another flow control method. Xon/Xoff characters in the data dictate the start and stop of data flow from the computer or terminal. Place DIP- Switch #2 in the DOWN position to select Xon/Xoff Flow Control. Hardware Flow Control (&E4) = Switch #2 UP Xon/Xoff Flow Control (&E5) = Switch #2 DOWN (Factory Default Setting = UP) Switch #2 SDLC/BSC Option (Synchronous Mode/Leased Line/Dial-Up) Synchronous Data Link Control (SDLC) and Binary Synchronous Control (BSC) are two error correction protocols used in the IBM Mainframe environment. Place DIP-Switch #2 in the UP position to enable SDLC mode, and place DIP-Switch #2 the DOWN position to enable BSC mode. SDLC Mode = Switch #2 UP BSC Mode = Switch #2 DOWN (Factory Default Setting = UP) Switch #3 Enable/Suppress Responses -- "Q" (Asynchronous Mode/Dial-Up) In some asynchronous mode applications, you may want to suppress all responses from the modem. Place DIP-Switch #3 in the DOWN position to enable result code responses (Q0). Place DIP-Switch #3 in the UP position, and answer mode is handled without responses and echo turned off (Q2), but originate is still intelligent. Enable Responses: Originate/Answer (Q0) = Switch #3 DOWN Suppress Responses: Answer (Q2) = Switch #3 UP (Factory Default Setting DOWN) Switch #3 dB Transmission Levels (Asynchronous/Synchronous Mode/Leased Line) DIP-Switch #3 adjusts dB transmission levels required by some phone carriers. Place DIP-Switch #3 in the DOWN position to enable 0 dB transmission. Place DIP-Switch #3 in the UP position to enable -10 dB transmission. 0dB Transmission = Switch #3 DOWN -10dB Transmission = Switch #3 UP (Factory Default Setting = DOWN) Switch #4 AS/400 Mode (Synchronous Mode/Leased Line/Dial-UP) The MT1432BA can function in the IBM AS/400 environment (appearing like an IBM5853 modem). First, DIP-Switch #7 must be placed in the UP position. This establishes an RTS/CTS condition (state typical for an IBM5853 modem in half-duplex mode). Next, place DIP-Switch #4 in the DOWN position. This "spoofs" the MT1432BA into operating like an IBM5853 modem in AS/400 applications. DIP-Switch #4 in the UP position disables this function. Note that the MT1432BA must be in Command mode to allow AS/400 mode (DIP-Switch #8 DOWN). AS/400 Mode Enabled = Switch #4 DOWN AS/400 Mode Disabled = Switch #4 UP (Factory Default Setting = UP) Switch #4 Unix UUCP Spoofing (Asynchronous Mode/Leased Line/Dial-Up) The MT1432BA can be configured for use with Unix equipment which employs ACK flow control to monitor data integrity. The MT1432BA can do "UUCP spoofing", where the modem is able to generate ACKs at the DTE interface. Data then is transmitted more time- efficiently, because the delay of waiting for data to be received then waiting for the ACK to be returned at the remote end, is eliminated. Place DIP- Switch #4 in the DOWN position to enable UUCP spoofing. UUCP Spoofing Enabled = Switch #4 DOWN UUCP Spoofing Disabled = Switch #4 UP (Standard Factory Setting = UP) Switch #5 Enable/Disable Auto-Answer - "Ans" (Asynchronous Mode/Synchronous Mode/Dial-Up) In some originate-only applications, you may wish to disable the MT1432BA's automatic answering capabilities. This may be true if you have a telephone set attached to a modem and wish to receive voice calls that you yourself would answer instead of the modem. Place DIP- Switch #5 in the UP position to enable Auto-Answer. Place DIP-Switch #5 in the DOWN position to disable Auto-Answer. Auto-Answer Enabled = Switch #5 UP Auto-Answer Disabled = Switch #5 DOWN (Factory Default Setting = UP) Switch #5 Originate/Answer Mode (Asynchronous/Synchronous Mode/Leased Line) The MT1432BA functions in either Originate or Answer mode. Place DIP-Switch #5 in the UP position to enable Originate mode. Place DIP-Switch #5 in the DOWN position to enable Answer mode. Originate Mode Enabled = Switch #5 DOWN Answer Mode Enabled = Switch #5 UP (Factory Default Setting = UP) Switch #6 Maximum Throughput Setting (Asynchronous Mode/Leased Line/Dial-Up) Some users have applications where they want to dial into services with maximum throughput on, and other applications where maximum throughput must be off (i.e., service not supporting error correction, and the V.42 handshake interferes with logon sequence). DIP-Switch #6 is used for switching between these two modes. This DIP-Switch controls three important parameters (error correction, speed conversion and serial port speed), which in effect enables or disables maximum throughput. Maximum Throughput Setting Enabled = Switch #6 UP Maximum Throughput Setting Disabled = Switch #6 DOWN (Factory Default Setting = UP) Switch #6 Slave Clocking (Synchronous Mode/Leased Line/Dial-Up) In Synchronous mode, DIP-Switch #6 controls the option of having timing controlled by the receive clock. The originate modem, in effect, adjusts to the answer (remote) modem. Place DIP-Switch #6 in the DOWN position to enable Slave Clocking. Place DIP-Switch #6 in the UP position to disable Slave Clocking. Slave Clocking Enabled = Switch #6 DOWN Slave Clocking Disabled = Switch #6 UP (Factory Default Setting = UP) Switch #7 Request To Send Forced - "RTS" (Asynchronous/Synchronous Mode/Leased Line/Dial-Up) If your computer or terminal uses RTS/CTS protocol (typically used in some synchronous applications, but also is using hardware pacing for V.42 error correction or speed conversion), you may want to set RTS to function independently of CTS (DIP-Switch #7 UP). For most applications, especially asynchronous, this switch should be set so that RTS is forced On (DIP-Switch #7 DOWN) RTS functions Normally = Switch #7 UP RTS forced On = Switch #7 DOWN (Factory Default Setting = DOWN) Switch #8 Enable/Disable Command Mode -- "Com" (Asynchronous/Synchronous Mode/Leased/Dial-Up) In some applications you may want to disable the MT1432BA's Command mode so that the modem does not recognize or react to "AT" commands or any other commands. This may be true in strictly auto-answer applications where no call origination is required. Place DIP-Switch #8 in the DOWN position to enable Command mode. Place DIP-Switch #8 in the UP position to disable Command mode. The factory default setting is Command mode enabled. Disable Command Mode = Switch #8 UP Enable Command Mode = Switch #8 DOWN (Factory Default Setting = DOWN) Switch #9 Digital Loopback Test (Asynchronous/Synchronous Mode/Leased Line/Dial-Up) In Synchronous mode, this switch controls both Local Digital Loop and Remote Digital Loop tests while on-line. When the Voice/Data switch is toggled to the Answer mode position (UP) and when DIP-Switch #9 is in the UP position, the MT1432BA performs the Local Digital Loopback test. When DIP-Switch #9 is DOWN and the Voice/Data switch is toggled to Answer mode (UP), the MT1432BA performs the Remote Digital Loopback test. Local Digital Loopback Test = Switch #9 UP Remote Digital Loopback Test = Switch #9 DOWN (Factory Default Setting = DOWN) Switch #10 Leased Line/Dial-Up Operation -- "DDD" (Asynchronous/Synchronous Mode/Leased Line/Dial-Up) The MT1432BA operates in either leased-line or dial-up modes. This switch controls leased-line/dial-up operation (used in conjuction with 2-position "Flip" Switch. See Section 8.6). Place DIP-Switch #10 in the UP position for Dial-Up operation. Place DIP-Switch #10 in the DOWN position for leased-line operation. Dial-Up Operation = Switch #10 UP Leased Line Operation = Switch #10 DOWN (Factory Default Setting = UP) Switch #11 "AT" Responses/Multi-Tech Responses (Asynchronous Mode/Leased line/Dial-Up) If you are in Asynchronous mode, the MT1432BA can be set to respond with Result Codes adhering to the "Multi-Tech" command responses (Switch #11 in the DOWN position), or to "AT" command responses (Switch #11 in the UP position). The &Q command performs the same function (choosing "AT" or "Multi- Tech" Result Codes), and is explained further in section 4.3 of this manual. "AT" Responses (&Q1) = Switch #11 UP "Multi-Tech" Responses(&Q0) = Switch #11 DOWN (Factory Default Setting = DOWN) Switch #11 Internal/External Clocking (Synchronous Mode/Leased Line/Dial-Up) In Synchronous Mode, the transmit clock can be supplied by the DTE on pin 24 of the RS232C/V.24 interface by placing DIP-Switch #11 UP. Place DIP-Switch #11 in the DOWN position to enable DCE to control clocking (internal clock via pins 15 and 17 of the RS232/V.24 interface). External Clock (pin 24) = Switch #11 UP Internal Clock (pins 15/17) = Switch #11 DOWN (Factory Default Setting = DOWN) Switch #12 Asynchronous/Synchronous Operation -- "Sync" (Asynchronous/Synchronous Mode/Leased Line/Dial-Up) The MT1432BA can operate in both Asynchronous and Synchronous mode. In Synchronous mode, start and stop bits are eliminated. The modem's internal clock circuits on the RS232C/V.24 pins 15 and 17 are activated. The MT1432BA's Command mode is not accessible in Synchronous mode. In Synchronous operation, you may want to set the RTS forcing and CTS forcing DIP- Switches so that both of signals act normally (not forced on). Synchronous Operation = Switch #12 UP Asynchronous Operation = Switch #12 DOWN (Factory Default Setting = DOWN) Switches #13 and #14 Speed Selection (Synchronous Mode/Leased Line) Switches #13 and #14 are used to set the modem's data transmission rate. Switches #13 and #14 are used in combination, typically in leased-line and call origination applications. Note that the modem baud rate command ($MB) overrides the setting of these speed selection switches (DIP switches #13 and #14). 14400 bps Operation = Switch #13 UP and Switch #14 UP 9600 bps Operation = Switch #13 DN and Switch #14 UP 4800 bps Operation = Switch #13 UP and Switch #14 DN 2400 bps Operation = Switch #13 DN and Switch #14 DN (Factory Default Setting = Switch #13 UP and Switch #14 UP) Switch #15 Carrier Detect/DSR Forcing -- "DSR" (Asynchronous/Synchronous Mode/Dial-Up/Leased Line) Some terminals react in unusual ways to the toggling of the Carrier Detect (CD - RS232C/V.24 pin 6) signals. The most common symptom is that the modem does not respond to commands, or does not echo characters. In these cases, it is advisable to force these two signals On in order for the terminal to communicate properly with the modem in Command mode. This is done by setting Switch #15 DOWN. Place Switch #15 in the UP position, and both CD and DSR will be either on or off, depending on the On- Line status. CD and DSR normal = Switch #15 UP CD and DSR forced On = Switch #15 DOWN (Standard Factory Setting = UP) Switch #16 This switch is not used (reserved for future use). 8.3 &W Lock/Unlock (EN/DIS) Jumper This jumper lets you lock parameters stored in modem memory. This is to prevent reconfiguring the MT1432BA from its factory default parameter settings. Parameters can be stored on a "temporary" basis, and not stored to memory. The MT1432BA retains its original set of parameters when the modem is powered off, or when the &W1Z command is issued. &W0 Jumper &W0 Jumper Lock ("EN") Position Unlock ("DIS") Position (Default Setting) (Option Setting) 8.4 Test/OOS (Out Of Service) Jumper When the MT1432BA is Out Of Service (OOS), it is busy to incoming calls. In the Test (option) setting, the modem drives pin 25 high when the modem is in Test mode. In the OOS (default) setting, the computer or terminal forces pin 25 high and put the modem in a busy condition. Note that jumper (shorting) plugs are not shipped with the MT1432BA, but are provided by Multi-Tech's Tech Support group on request. Test/OOS Jumper Test/OOS Jumper "OOS" (OOS "Input") Position "Test" (OOS Output) Position (Default Setting) (Option Setting) 8.5 MI/MIC Jumper The MT1432BA is available with a modified dial-up phone line interface, called the "MI/MIC" option. The MI/MIC jumper enables or disables the Mode Indicate/Mode Indicate Common (MI/MIC) interface. This option is for applications where the modem's dialing capability is not used, and dialing is done by an external device (such as an 801 dialer, a computer, or a PBX/CBX system dialer). To activate the MI/MIC option, first move the two jumper plugs in the MIC position. The command $MI, then controls this function. Entering AT$MI1 enables MI/MIC operation.To disable the MI/MIC option, place the two shorting plugs in the MI position and enter AT$MI0 (default). MI/MIC Option Jumper MI/MIC Option Jumper MI/MIC Option Disabled MI/MIC Option Enabled (Factory Default Setting) (Option Setting) Note that jumper (shorting) plugs are not shipped with the MT1432BA, but are provided by Multi-Tech's Tech Support group on request. 8.6 Dial/Leased Line Switch The two-position DIAL/LEASED "flip" switch is used (in conjunction with DIP-Switches #5 and #10) to select the type of phone line connection (either dialup or leased line). Refer to section 3.3 for more information on phone line connections. The DIAL/LEASED switch is located adjacent to the 16-position DIP-Switch (see Figure 8-1). For leased line operation, select the LEASED position. For dial-up line operation, select the DIAL position. The DIAL position is the factory default setting. DIAL DIAL LEASED LEASED DIAL/LEASED Switch DIAL/LEASED Switch DIAL Position LEASED Position (Factory Default Setting) (Option Setting) 8.7 Speaker Volume Control You can adjust the volume of the MT1432BA's phone-line monitor speaker with the volume control knob, located on the back of the modem next to the RS232C connector. Turn the knob clockwise to increase the modem's volume and counterclockwise to decrease volume. 8.8 Notes on Your Option Configurations This section lets you record any changes you may have made to the DIP-switch settings. Circle the appropriate setting and record the effect for future reference. DIP-Switches Switch Function Position Effect #1 Force DTR/DTR from Interface* UP* DOWN #2 Flow Control &E4*/&E5 UP* (Async/Dial-Up/Leased Line) DOWN #2 SDLC*/BSC (Sync) UP* DOWN #3 Result Codes Enable*/Disable UP (Async/Dial-up) DOWN* #3 DbM Transmit 0 dB*/-10dB UP (Async/Sync/Lease-Line) DOWN* #4 UUCP Enable/Disable* UP* (Async/Dial-Up/Leased Line DOWN #4 AS/400 Enable/Disable* UP* (Sync/Dial-Up/Leased line) DOWN #5 Auto-Answer Enable*/Disable UP* Async/Sync/Dial-Up) DOWN #5 Originate/Answer* UP* (Async/Sync/Leased Line) DOWN #6 Max-Thru Enable*/Disable UP* (Async/Dial-Up/Leased) DOWN #6 Slave Clock Enable/Disable* UP* (Sync/Dial-Up/Leased) DOWN #7 RTS/Normal/Forced* UP (Sync/Async/Dial/Leased) DOWN* #8 Command Mode Enabled* UP (Sync/Async/Dial/Leased) DOWN #9 Local/Remote* LoopBack UP (Async/Sync/Dial/Leased) DOWN* #10 Dial-Up*/Leased-Line UP* DOWN #11 "AT"/"Multi-Tech" Result Codes* UP (Asynchronous) DOWN* #11 Internal*/External Clocking UP (Synchronous) DOWN* #12 Sync/Async Mode* UP DOWN* DIP Switches #13-16 Switch Position Effect #13/#14 UP 14400 bps Operation UP* #13/#14 DOWN 9600 bps Operation UP #13/#14 UP 4800 bps Operation DOWN #13/#14 DOWN 2400 bps Operation DOWN #15 UP* CD/DSR from Interface (Sync/Async) #15 DOWN CD/DSR Forced On #16 UP Not #16 DOWN Used *Factory Default Setting Appendix C Command Summary COMMAND VALUES DESCRIPTION AT Attention Code that precedes most command strings except A/, A: and Escape Codes. RETURN Pressing RETURN key executes most commands. $ This symbol placed in dialing string enables the modem to detect AT&T's "call card" tones for accessing user's calling card to originate an on-line connection. A Answer call, even if no ring present. A/ Repeat last command. (Do not precede this command with AT. Do not hit RETURN to execute.) A: Continuous redial (10 redials in DOC units) of last number until answered. (Not used Internationally.) $An n = 0 or 1 ***$A0 discards data during auto-reliable time period. $A1 buffers data during auto-reliable time period. #An n = 0 thru 3 ***#A0 selects initial handshake at 14400 to 12000 to 9600 to 4800 to 2400 to 1200 to 300 bps. #A1 selects initial handshake at 14400 bps only. #A2 selects initial handshake at 14400 to 9600 to 4800 bps. #A3 selects initial handshake at 2400 to 1200 to 300 bps. Bn n = 0 or 1 ***B0 selects V.21 answer tone. B1 selects Bell answer tone. &Bn n = 0 or 1 ***&B0 means normal transmit buffer size. &B1 means reduced transmit buffer size. &BSn n = 0 or 1 &BS0 means maximum transmit block size of 64 characters. ***&BS1 means maximum transmit block size of 256 characters. $BAn n = 0 or 1 ***$BA0 means speed conversion is on. $BA1 means speed conversion is off. &Cn n = 0, 1, &C0 forces Carrier Detect on. 2, or 4 ***&C1 lets Carrier Detect act normally. &C2 lets Carrier Detect drop S24 time on disconnect. &C4 resets modem when Carrier Detect drops. Ds s = phone # Dial a telephone number "s," where s may include up to 60 digits or T, P, R, comma and ; characters. DsNd s = phone # Store telephone number. To store, phone d = 0 thru 9 number "s" is entered and followed by N and then Directory Number "d." &Dn n = 0, 2, or 3 *&D0 DTR is ignored &D1 means modem returns to command mode. ***&D2 lets modem react to DTR normally. &D3 causes modem to reset to modem default parameters. $Dn n = 0 or 1 ***$D0 disables DTR Dialing. $D1 enables DTR Dialing. En n = 0 or 1 E0 means do not echo Command Mode Character. ***E1 means do echo Command Mode characters. &En n = 0 thru 15 &E0 means no error correction. ***&E1 means V.42 Auto-reliable Mode. &E2 means V.42 Reliable Mode. &E3 means no modem-initiated flow control. ***&E4 means CTS modem-initiated flow control. &E5 means Xon/Xoff modem-initiated flow control. ***&E6 means Xon/Xoff not passed through. &E7 means Xon/Xoff passed through. ***&E8 means Enq/Ack pacing off. &E9 means Enq/Ack pacing on. ***&E10 means Normal Mode flow control off. &E11 means Normal Mode flow control on. ***&E12 means Pacing off. *&E13 means Pacing on. &E14 means data compression disabled. ***&E15 means data compression enabled. $EBn n = 0 or 1 ***$EB0 enables 10 bit mode. $EB1 enables 11 bit mode. %En n=0 thru 5 %E0 = Modem Won't Escape. ***%E1 = +++ Method (default setting). %E2 = Break Method. %E3 = Either +++ or Break Method. %E4 = No "OK" Response to +++ %E5 = "OK" Response to +++ #Fn n = 0 thru 2 #F0 means no fallback when on-line. #F1 means fallback from 14400 to 4800 bps when on-line. ***#F2 means fallback to 4800 bps from 14.4K bps/fall forward when line improves. &Fn n = 0, 8 or 9 &F loads factory default values from ROM. ***&F8 reads factory default values and switch settings when &F is issued. &F9 reads parameters stored in non-volatile memory when &F is issued. $Fn n = 0 or 1 $F0 means do not fall back to normal connect if CR received. ***$F1 means fall back to normal connect if CR received. &Gn n = 0, 1 or 2 ***&G0 turns off CCITT guard tones. &G1 turns on CCITT 550 Hz guard tone. &G2 turns on CCITT 1800 Hz guard tone. Hn n = 0 or 1 H0 means Hang Up (go on hook). H1 means Go Off Hook. $Hn n = 1 thru 3 $H1 brings up Help Screen #1. $H2 brings up Help Screen #2. $H3 brings up Help Screen #3. In n = 0,1 or 2 I0 displays Multi-Tech generic modem ID #. I1 displays firmware revision #. I2 displays modem model number. L Lists all stored telephone numbers in memory. L5 L5 lists all current operating parameters. L6 L6 lists all current S-Register values. L7 L7 lists additional parameters. L8 L8 lists on-line diagnostics. #Ln n = 0 thru 3 ***#L0 means modems negotiate V.42 Mode. #L1 means MNP on and LAP-M off. #L2 means LAP-M on and MNP off. #L3 means no detection phase but go directly to LAP-M. Mn n = 0 thru 3 M0 means Monitor speaker always Off. ***M1 means Monitor speaker On until carrier detected M2 means Monitor speaker always On. M3 Monitor speaker on during dialing/off during handshaking. $MBn n = speed $MB75 selects CCITT V.23 mode. $MB300 selects 300 bps on-line. $MB1200 selects 1200 bps on-line. $MB2400 selects 2400 bps on-line. $MB4800 selects 4800 bps on-line. $MB9600 selects 9600 bps on-line. ***$MB14400 selects 14400 bps on-line. &Mn n = 0 or 1 ***&M0 selects Async when on-line. &M1 selects Sync when on-line. $MIn n = 0 or 1 ***$MI0 disables MI/MIC option $MI1 enables MI/MIC option Nd d = 0 thru 9 Dial stored telephone number "d" (Do not include the letter D in this command.) NdNe d = 0 thru 9 Number Linking. If first number dialed is e = any other busy, another stored number may be number 0 automatically dialed. In example, stored thru 9 number d is dialed, and if busy, stored number e is dialed. O Exit Command Mode and go into On-Line Mode. P ***Modem will pulse-dial numbers following the P. &Pn n = 0 or 1 ***&P0 means 60-40 pulse ratio. &P1 means 67-33 pulse ratio. Qn n = 0, 1 or 2 ***Q0 means Result Codes sent. Q1 means Result Codes will be suppressed (quiet). Q2 means Dumb Answer Mode. &Qn n = 0 or 1 ***&Q0 selects "Multi-Tech" command set. &Q1 selects "AT" command set. Rn n = 0 or 1 ***R0 means modem will not reverse modes. R1 means modem will reverse modes. &Rn n = 0, 1 or 2 &R0 lets Clear to Send act normally. ***&R1 forces Clear to Send on. &R2 drops for 1 second on disconnect. $Rn n = 0 or 1 ***$R0 means disconnect after 12 retransmits. $R1 means do not disconnect after 12 retransmits. &RFn n = 0 or 1 &RF0 selects CTS follows RTS. ***&RF1 selects CTS to act independently Sr=n r = 0-11, 13, Sets value of Register "r" to value of "n", 15-17, where "n" is entered in Decimal format. 24-26, 29, 30, 32, 34... Sr? r = 0-11, 13, Reads value of Register "r" and displays 15-17, 24- value in 3-digit Decimal format. 26, 30, 32 or 34... $SBn n = speed $SB300 selects 300 bps at serial port. $SB1200 selects 1200 bps at serial port. $SB2400 selects 2400 bps at serial port. $SB4800 selects 4800 bps at serial port. $SB9600 selects 9600 bps at serial port. $SB19200 selects 19,200 bps at serial port. $SB38400 selects 38,400 bps at serial port ***$SB57600 selects 57,600 bps at serial port. &SFn n = 0 or 1 ***&SF0 selects DSR follows CD. &SF1 selects DSR independent. &Sn n = 0, 1 or 2 &S0 forces Data Set Ready On. ***&S1 lets Data Set Ready act normally. &S2 Data Set Ready drop is regulated by S24 on disconnect. $SPn n = 0 or 1 ***$SP0 disables UUCP Spoofing $SP1 enables UUCP Spoofing Modem will tone-dial numbers following the T. &Tn n = 4 or 5 &T4 means Enable Response to Request for Remote Digital Loopback. ***&T5 means Disable Response to Request for Remote Digital Loopback. #Tn n = 0 or 1 #T0 turns off Trellis Coded Modulation ***#T1 turns on Trellis Coded Modulation Un n = 0, 1, 2, U0 places modem in Analog Loop Originate or 3 Mode. U1 places modem in Analog Loop Answer Mode. U2 places modem in Remote Digital Loopback test mode. U3 places modem in Local Digital Loopback test mode. $VDn n= 0 or 1 $VD0 disables Voice/Data Dialing $VD1 enables Voice/Data Dialing Vn n = 0 or 1 V0 means Result Codes sent as digits (terse response). ***V1 means Result Codes sent as words (verbose response). W Wait for new dial-tone. &Wn n = 0 or 1 &W0 causes modem to store its current parameters in non-volatile RAM, and modem will load these for future sessions instead of reading factory ROM defaults, unless &F command used. ***&W1 causes modem to not store parameters. Xn n = 0, 1, 2, ***X0 selects Basic Result Codes 3 or 4 (w/o CONNECT 1200, CONNECT 2400). X1 selects Extended Result Codes (w/CONNECT 1200, CONNECT 2400). X2 selects Standard AT Command set with NO DIAL TONE. X3 selects Standard AT Command set with BUSY. X4 selects Standard AT Command set with NO DIAL TONE and BUSY. #Xn n= 0 or 1 ***#X0 selects single XOFF character sent until XON level returns. #X1 selects multiple XOFF characters after buffer level is full. Yn n = 0 or 1 ***Y0 disables sending or responding to long space "break". Y1 enables sending or responding to long space "breaks". Z All configuration parameters are reset to default values. COMMAND DESCRIPTIONS , in Dial Causes pause during dialing. command ; in Dial Causes return to Command Mode after command dialing. ! in Dial Causes modem to flash On-Hook. command @ in Dial Causes modem to wait for ringback, then 5 command seconds of silence before processing next part of command. +++AT In-band Escape Sequence. Places modem in Command Mode while still remaining On- Line. Enter +++ followed by the letters A and T, up to ten command characters, and a RETURN. BREAK AT Out-of-band Escape Sequence. Places modem in Command mode while still remaining On- Line. Not preceded by AT. Enter a BREAK signal, followed by the letters A and T, up to sixty command characters, and hit RETURN. Callback Security/Remote Configuration Command Summary Command Description #DBn #DB0 disables Callback Security and answering Yes to the prompt turns off Callback Security and erases stored phone numbers and passwords. Answering No to the prompt aborts the command. #DB1 activates remote and local password security. #DB2 activates remote password security. #CBNyyxxxxxx Callback password with xxxxxx being callback password and yy being the memory location. Callback password xxxxxx must start with a non-numeric character and upper/lower case sensitive. Callback password xxxxxx must be a minimum of 6 and maximum of 10 characters. yy memory locations are from 0 to 29. Must specify P (pulse) or T (tone) dialing in string. + - Dxxxxxx???Nxx Callback Phone Numbers xxxxxx with the + preceding the phone number indicating the callback modem phone number for the corresponding password at the same memory location. The (-) preceding the phone number enables direct entry when the caller uses the correct password without the callback modem having to return the call. The ??? entry at the en d of the phone number represents an extension added to the main phone number. The Nxx is the memory location of the callback phone number and password. Command Description #Pn Parity of the prompt messages sent by the callback modem. #P0 is no parity #P1 is odd parity #P2 is even parity #RCBNxx Erases the callback password stored at memory location xx. Memory locations are 0 to 29. #RDNxx Erases the callback phone number stored at memory location xx. Memory locations are 0 to 29. Password Command Summary Command Description #Ixxxxxxxxxx Login Password is any keyboard characters (x) (upper/ lower case sensitive), minimum 6 and maximum 10 characters. The default Login Password is MULTI-TECH. #Syyyyyyyyyy Set-up Password is any keyboard characters (y) (upper/ lower case sensitive), minimum 6 and maximum 10 characters. The default Set-up Password is MODEMSETUP. V.25bis Commands Command Description $Vn $V0 returns modem to AT command mode when in V.25bis mode. $V1 enables V.25bis mode of operation. $V2 allows modem to receive one V.25bis command while in AT command mode without leaving AT command mode. $V5 DSR follows DTR in V.25bis mode. $V6 DSR does not follow DTR in V.25bis mode. CLAmm Clears the phone number memory location mm. Phone numbers are stored in memory locations 00 to 19. CSPs Changes the serial bps rate. CSP0300 - 300 bps CSP1200 - 1200 bps CSP2400 - 2400 bps CSP4800 - 4800 bps CSP9600 - 9600 bps CSP19200 - 19200 bps CSP38400 - 38400 bps CSP57600 - 57600 bps CSP115200 - 115200 bps CRNdd Dials phone number dd where dd can be up to 20 characters (0 through 9, *, #, P, T and :). Phone number is checked against the Delayed and Forbidden Number lists before dialed. Command Description CRIdd;nn Dials dd same as CRN Command and ignores nn identification string. CRSmm Dial stored phone number at memory location mm. Phone numbers are stored in memory locations 00 to 19. Phone number is checked against the Delayed and Forbidden Number lists before dialed. PRNmm;dd Store phone number in memory location mm followed by a semicolon (;) and the phone number dd in which you wish to store. RLN Displays all phone numbers stored in memory. RLD Displays the delayed phone numbers stored in memory. The delayed phone numbers listing can contain up to eight phone numbers. RLF Displays the forbidden phone numbers stored in memory. This listing can be up to eight phone numbers. DIC The disregard or connect to incoming calls or commands are used for auto-answer CIC operations. DIC stops the modem from answering incoming calls. CIC causes the modem to answer incoming calls. Appendix D DIP-Switch Summary DIP-Switch Condition Effect Asynchronous Mode #1 *UP DTR dependent on interface Down DTR forced On at all times #2 *UP Hardware Flow Control Down Xon/Xoff Flow Control #3 UP -10 dB Transmission (leased line) *Down 0 dB Transmission (leased line) #4 *UP UUCP Spoofing Off Down UUCP Spoofing On #5 *UP Automatic Answer On Down Automatic Answer Off #6 *UP Max throughput On Down Max throughput Off #7 UP RTS dependent on Interface *Down RTS forced On at all times #8 UP Disable Command Mode *Down Enable Command Mode #9 UP Local Digital Loopback On *Down Remote Digital Loopback On #10 *UP Dial-Up Operation Down Leased Line Operation #11 UP "AT" Responses *Down "Multi-Tech" Responses #12 UP Synchronous Mode On *Down Asynchronous Mode On DIP-Switch Condition Effect Synchronous Mode #1 *UP DTR Dependent On interface Down DTR forced On at all times #2 *UP SDLC Mode On Down BSC Mode On #3 UP Command Mode Response Off *Down Command Mode Response On #4 *UP AS/400 Mode Off Down AS/400 Mode On #5 *UP Answer Mode On Down Originate Mode On #6 *UP Slave Clocking Off Down Slave Clocking On #7 UP RTS Dependent on interface *Down RTS forced on at all times #8 UP Command Mode Off *Down Command Mode On #9 UP Local Digital Loopback On *Down Remote Digital Loopback On #10 *UP Dial-Up Operation Down Leased Line Operation #11 UP External Clock selected *Down Internal Clock selected #12 UP Synchronous Mode On *Down Asynchronous Mode On Appendix E S-Register Summary S-REGISTER UNIT RANGE DEFAULT DESCRIPTION S0 1 ring 0-255 1 Sets number of rings before modem answers. S1 1 ring 0-255 0 Counts rings which have occurred. S2 ASCII 0-127 43 Sets Escape Code character (default is plus + sign). S3 ASCII 0-127 13 Sets character recognized as RETURN (default is CTRL-M). S4 ASCII 0-127 10 Sets character recognized as LINE FEED (default is CTRL-J). S5 ASCII 0-32 8 Sets character recognized as 127 BACKSPACE (default is CTRL-H). S6 1 second 2-255 2 Determines wait-time for 4-255** 4** dial tone. S7 1 second 1-255 45 Determines how long modem 1-45* waits for carrier before aborting call. S8 1 second 0-255 2 Sets pause time caused by a 4-255** 4** comma character in a dial command. S9 100 mSec 1-255 6 Sets carrier detect response time. S10 100 mSec 1-255 7 Sets delay time between when carrier is lost and when modem disconnects. S11 1 mSec 1-255 70 Sets time duration of and 80-255* 80* spacing between tones in tone-dialing. S13 ASCII 0-127 37 Defines Remote Configuration Escape Character S15 Sec 10-255 20 Defines time delay for Callback attempts after initial passwords have exchanged. S16 1 Attempt 1-255 4 Defines the number of Callback attempts after initial passwords have exchanged between modems. S17 10 mSec 0-2.5 250 mSec Defines length of break time (space) to PC. S24 50 mSec 0-255 20 Sets DSR/CTS/CD dropout time. Default (20) equals one second. S25 100 mSec 0-255 0 Sets DTR dropout time. 0 default equals 50 mSec. S26 1 0-255 0 Specifies number of failed password attempts allowed. S29 1 1-255 20 Specifies the amount of idle time can elapse between AT com- mands after the SETUP password has been entered. S30 min 0-255 0 Inactivity timer used to disconnect modem. S32 100mSec 0-255 20 Sets time that modem waits for a to be entered during escape sequence execution. S34 ASCII 0-60 10 Buffer size for number of characters in AT command string after on-line escape sequence, before buffer is cleared and escape sequence aborted. S36 1 second 0-255 0 S36 sets the time between DTR inactive and the modem going off-hook (busy-out). S37 1 second 0-255 5 S37 sets the time allowed DTR active and the modem responding on-hook (not busy). Appendix F Result Code Summary (TERSE) (VERBOSE) DIGIT WORDS EFFECT 0 OK Command was executed without error; ready for next command. 1 CONNECT Modem has detected carrier and gone on-line. 2 RING Modem has detected ring caused by incoming call. 3 NO CARRIER No carrier signal has been detected within allowed time. 4 ERROR Error in Command line (too many, or invalid characters). 5 CONNECT 1200 Modem has detected carrier at 1200 bps and gone on-line. 6 NO DIAL TONE No dial tone has been detected. 7 BUSY A busy signal has been detected. 8 NO ANSWER Remote system did not answer. 9 CONNECT 2400 Modem has detected carrier at 2400 bps and gone on-line. 11 CONNECT 4800 Modem has detected carrier at 4800 bps and gone on-line. 12 CONNECT 9600 Modem has detected carrier at 9600 bps and gone on-line. 13 CONNECT 14400 Modem has detected carrier at 14400 bps and gone on-line. 23 CONNECT 1275 Modem is connected in V.23 mode. Note: If MT1432BA is used in Reliable mode, the following responses change: 1R CONNECT RELIABLE 5R CONNECT 1200 RELIABLE 9R CONNECT 2400 RELIABLE 11R CONNECT 4800 RELIABLE 12R CONNECT 9600 RELIABLE 13R CONNECT 14400 RELIABLE If MT1432BA is used in LAP-M reliable mode, the following responses change: 1L CONNECT LAPM 5L CONNECT 1200 LAPM 9L CONNECT 2400 LAPM 10L CONNECT 4800 LAPM 12L CONNECT 9600 LAPM 13L CONNECT 14400 LAPM Note 1: If the MT1432BA is used with data compression, the word COMPRESSED or the letter C is added to result codes. Note 2: If the Standard "AT" Command Set 2400 responses are selected with the &Q command, the following responses change: 9 (not used) 10 CONNECT 2400 Modem has detected carrier at 2400 bps and gone on-line. Appendix G V.25bis Operation Chapter 4 described a set of commands which let the MT1432BA dial, hang-up, and be configured for various applications. However, these commands, the AT command set, are only functional when the DTE transmits data asynchronously. That is, they cannot be used with synchronous equipment such as that found in IBM's Binary Synchronous Communications (BSC) and Synchronous Data Link Control (SDLC)* environments. The CCITT V.25bis commands provide you with an alternate set of commands and responses to those described in Chapter 4 for applications in which the DTE is synchronous. V.25bis commands support dialing functions in asynchronous or synchronous mode according to the recommendations of the CCITT (Consultative Committee of International Telephony and Telegraphy); however, the AT commands are understood to reign in the asynchronous world, while the V.25bis commands are relegated to the synchronous world of datacomm. If you need to establish a datacomm link over Public Switched Telephone Network (PSTN) dial-up services, and your equipment outputs a synchronous data stream, V.25bis commands are essential. V.25bis mode AT commands do not include any modem configuration commands. You can execute normal AT commands in V.25bis mode for modem configuration. Delayed and Forbidden Numbers V.25bis provides the facility to delay failed call retry attempts by putting numbers that failed to connect on a special Delayed Number list. Subsequent dialing of these numbers will be delayed (time specified by a country regulation) and an appropriate message displayed. If the number is retried more than the maximum allowed number of times (number is also specified by country regulation), it is placed on the Forbidden Numbers list, and no further retries will be allowed. When the Forbidden Numbers list is full, no dialing is allowed and a CFIFF indication is given. The modem in AT command mode will respond with NO CARRIER. If country regulations require that the Forbidden Numbers list be checked in AT mode, then NO CARRIER will be the response to a dial attempt in AT mode. Numbers will also be put on the Forbidden Numbers list if the Delayed Numbers list is full and a new number fails for the first time. In that case, the new number will be added to the Delayed Number list and the oldest existing number added to the Forbidden Numbers list. Numbers are removed from the Forbidden Numbers list by after a certain time has past (also by country regulation). Some country regulations have numbers remain on the Forbidden Numbers list permanently. The Delayed Number and Forbidden Numbers lists are eight numbers long (20 characters each). V.25bis Operation Operation in V.25bis mode is similar to AT command mode in that certain DIP switch functions are important to its operation. V.25bis does not include any speed detection for asynchronous mode, so when you are giving commands, you must stay in your initial speed (i.e., if you change your terminal speed while entering an AT command, you will get no responses). In synchronous mode, the modem supplies the clock, to the synchronous terminal "knows" the speed. You must be in V.25bis mode for the commands described here to function. Most AT commands will also function, except those associated with dialing such as ATD, ATN, ATO, and ATU. To get into V.25bis mode, you type AT$V1. At this point your modem does no more speed or parity detection (things associated with asynchronous operation). To get out of V.25bis mode and back into AT command mode, enter AT$VO. The AT$V2 command allows you to run one V.25bis command from AT command mode without leaving AT command mode. There is no command to select between asynchronous and synchronous V.25bis operation. The position of DIP-Switch #12 selects between modes. For synchronous mode, DIP-Switch #12 must be UP, and the AT command mode enabled. Another asynchronous mode concern is the problem of connecting at a different speed than the speed at which the serial port is set. If your modem port speed is different from the serial port speed, you must either: 1. Enable speed conversion and have flow control on, or 2. Enable connect responses (with the ATX1 command) and change the serial baud rate after receiving a connect message. DTR dialing is functional in V.25bis mode, except the number dialed is from the V.25bis mm memory location 01. Also, if the $VD1 command is entered when in Auto-Answer mode, the modem answers immediately upon receiving the first ring. There is no disconnect message (NO CARRIER) if a normal connection is made. V.25bis Set-Up and Initialization Before you operate your modem in the V.25bis mode, you need to make sure it is set-up properly (various RS232 lines such as DSR and CTS act as specified in the V.25bis standard). Set-up involves proper DIP- Switch settings, jumper plug settings and soft-switches (software controlled conditions). V.25bis DIP-Switches #1 - Unforced DTR #2 - NA #3 - NA #4 - NA #5 - Auto-Answer enabled #6 - Async - Max throughput set Sync - Slave Clocking #7 - RTS unforced #8 - Command Mode forced #9 - Digital Loopback Off #10 - Dial-Up #11 - Async - "AT"/"Multi-Tech" Resp. #12 - Async/Sync mode set per requirements V.25bis Mode AT Commands The following commands will either alter standard V.25bis behavior (so you must be careful in their use) or they are not allowed, as indicated. All other commands can be used in V.25bis operation. A Not Allowed A/ Not Allowed A: Not Allowed D Not Allowed D...N Not Allowed $D Alters Operation ($D1 in V25bis is direct call mode) E Alters Operation &F Alters Operation (removes modem from asynchronous V.42bis mode) N Not Allowed N...N Not Allowed O Not Allowed P Not Allowed T Not Allowed U Not Allowed W Not Allowed X Alters Operation (X0 no connect message) (X1 connect message) , Not Allowed ; Not Allowed ! Not Allowed @ Not Allowed +++AT Not Allowed V.25bis Responses (Result Codes) When in V.25bis mode (the AT$V1 command executed), your modem provides you with several responses which can help you follow the progress of V.25bis operations. These are similar to the Result Codes associated with AT Command mode operation. The V.25bis responses are in the form of three-character mnemonics as listed below: INC Incoming Call (same as RING indicator) VAL A valid V.25bis command has been attempted DLCt Call delayed for t minutes (number on Delayed list) CFlrr Call failure indicator where rr equals: et - Engaged tone (same as BUSY) nt - Call Answered but No Answer Tone ab - Call Not Answered fc - Number on Forbidden List ns - Number not stored in memory ua - User Abort nd - No Dialtone ff - Forbidden List full LSNmm;dd...dd Phone number in V.25bis memory LSDmm;dd...dd Phone number on the Delay list LSFmm;dd...dd Phone number on the forbidden list CON ssss Connection at ssss speed (if X1 in effect) V.25bis AT Commands The AT commands associated with V.25bis mode are described as follows. Note that one command enables and disables V.25bis mode and the rest are only operable in the V.25bis mode. Enable/Disable V.25bis Mode ($V) Command The function of the $V command is to select the V.25bis mode in asynchronous mode. (Synchronous mode is set up with switches. For example, the modem could be in AT command mode, (AT$V1), and if synchronous mode is enabled with AT Command mode enabled, then V.25bis mode is selected). Prior to executing this command, make sure that your modem is properly set up to perform the type of operation you will be performing. Refer to the initialization section of this appendix for information about modem set-up. When in V.25bis mode, most normal AT commands will also function (except D,N,O and U). V.25bis operates in asynchronous or synchronous modes (depending on the position of DIP-Switch #12), and does not check for terminal speed (so do not change speeds while in this mode) or parity. In synchronous mode, speed is not important since the internal clocks provide synchronization. To place your modem in V.25bis mode from asynchronous mode, enter the AT$V1 command. To return to AT command mode, enter the AT$V0 command. AT$V2 allows you to run one V.25bis command from AT command mode without leaving AT command mode (the V.25bis command follows $V2 on the command line). Clear Number in Memory (CLA) Command The CLA command clears a specific number in the mm phone number memory by entering CLAmm. Change Serial Baud Rate (CSP) Command The CSP command will change the serial baud rate of your modem by entering CSPsssss where sssss can equal: 0300 = 300 bps 1200 = 1200 bps 2400 = 2400 bps 4800 = 4800 bps 9600 = 9600 bps 19200 = 19200 bps 38400 = 38400 bps 57600 = 57600 bps Dial Phone Number Provided (CRN) Command The CRN command permits the dialing of the phone number immediately following it (from the command line). It is similar to the D command of the AT command set, except that the number is first checked against the Delayed Number and Forbidden Number list. If permitted, depending on the country regulations in effect, the number will then be dialed. For example, if you enter CRN7859875 and hit RETURN, your modem will check the two lists. If the number is on the Delayed Numbers list, you can dial that number again after t minutes have passed. If the number is on the Forbidden list, a CFIFC message will be displayed. You can use various commands from the AT command set within the CRN command line to facilitate the dialing process, such as P, T, or : for pulse dialing, tone dialing and wait for dial tone. V.25bis supports "smart" dialing. To dial a phone number, enter CRNdd...dd where dd...dd is the phone number, which can be up to 20 characters long using any character on the telephone pad (0 through 9, *, #, P, T, and :). Some additional dialing characters may be available, based on country regulations. Dial Phone Number Stored in Memory (CRS) Command A telephone number that you have stored in the modem's memory may be automatically dialed after checking it against the Delayed and Forbidden number lists by entering CRSmm where mm = 01, 02, 03, 04,....20. For example, a number stored in mm location 15 would be entered by CRS15 and hitting RETURN, then, if the number in mm memory location 15 is not on either list, it will be automatically dialed. Store a Phone Number in Memory (PRN) Command Your modem has a special V.25bis memory for storing phone numbers which you may dial by using the CRS command. The memory holds up to 20 numbers of 20 characters each. You can store phone numbers in this memory with the PRN command. The format for the command is PRNmm;dd...dd where mm is the memory location at which you wish to store a number (any digits 01 through 20) followed by a semicolon(;) and then dd...dd (the number to be stored up to 20 digits long). The number can include punctuation as required. To clear a number from the V.25bis memory, see the CLA command. Listing Numbers Stored in Memory (RLN) Command Telephone numbers that you have stored in the modem's V.25bis memory may be listed and displayed with the RLN command. It will display all twenty mm storage location numbers and associated telephone numbers with any command letters and punctuation imbedded in each number. The RLN command is similar to the L command of the AT command set. To list the V.25bis stored telephone numbers, enter RLN and hit RETURN. Listing Delayed Phone Numbers (RLD) Command When a phone number is dialed either by a CRN or CRS command and a connection is not made, the number is entered in the modem's V.25bis Delayed Number list along with the number of retry attempts. Any further dialing attempts will be delayed some amount of time (determined by the regulations of each country). While the delay is in progress, the modem will give a DLC indication. The list contains eight numbers. When filled, the next number failing "bumps" off the oldest number on the list onto the Forbidden Number list. Numbers on the Delayed Number list that succeed in a connect attempt are removed. If a certain number of failed attempts occur (the number of failed attempts is specified by each country), the number is entered into the V.25bis Forbidden Phone Number List. Forbidden phone numbers cannot be dialed at all. To list the phone numbers on the V.25bis Delayed Phone Number List, enter RLD and hit RETURN. Listing Forbidden Phone Number (RLF) Command Those phone numbers that have failed to connect the required number of times as specified by country regulations are removed from the Delayed Number list and entered onto the V.25bis Forbidden Number list. Numbers on the Forbidden Number list cannot be dialed at all for some maximum amount of time, which is also specified by country regulations. In some countries, the time might be one hour, and in others the number may never be dialed again. The forbidden list is eight numbers long, with the newest number replacing the oldest if the memory is full. To list the numbers in the Forbidden list enter RLF and hit RETURN. Disregard or Connect to Incoming Calls (DIC or CIC) Command The Disregard or Connect to Incoming Calls commands are used for Auto-Answer operations. Depending on the country regulations, your modem will wait some amount of time or number of rings before answering the call. During that time, you can stop the modem from answering the call by entering the DIC (Disregard Incoming Calls) command. The CIC (Connect to Incoming Calls) command will cause your modem to answer the call (either reversing the effect of a DIC command or simply have your modem answer the call immediately without waiting the regulation time before answering). DTR Dialing ($D) Command DTR Dialing is an alternate method of causing the MT1432BA to automatically dial a number. Data Terminal Ready (DTR) is a signal that comes into the modem from the terminal or computer to which it is connected via pin 20 of the RS232 interface. In DTR Dialing, the modem will automatically dial a stored number as soon as it receives a high DTR signal. The DTR Dialing method is popular when using the MT1432BA in synchronous applications. To enable DTR Dialing, enter the command AT$D1 and hit Return. The modem will now dial the phone number you have stored as N0 when it receives a high DTR signal (see the D...N command in Chapter 4). DTR must remain high for the duration of the call, until disconnect. To disable DTR Dialing, enter the command AT$D0 (or AT$D) and hit RETURN. When you use DTR Dialing, be sure that DIP-Switch #1 is in the UP position, so that DTR is not forced on. In addition, when using DTR Dialing in a synchronous application, be sure that DIP-Switch #8 is in the UP position to disable V.25bis Command mode. CCITT V.25bis Country Specific Information Due to the flexibility of the V.25bis standard, each country may establish specific regulations governing the way operations are handled. The purpose of this document is to detail each country's specific regulations that affect operation of V.25bis in Multi-Tech modems. 1. Italy a) Command/Indication modifications 1. Phone number indications include status ;ZPSTTT a) Z - U, D, or F, for Unrestricted, Delayed or Forbidden b) P - Delay time if delayed c) S - Number of retries so far d) TTT - Interdiction time to further attempts 2. Modify RLN command to allow memory location parameter a) RLNmm is now valid to list one number in memory 3. PRN and CLA commands do not work on active memory locations a) Active number are ones who are on the delay or forbidden lists 4. Added dialing digit '<<' to indicate 2 second pause b) Delayed and Forbidden list behavior 1. 5 retries without delay 2. 2 minute delay between next 4 retries 3. After 9 retries the number is put on the forbidden list 4. 120 minute timer is started on entry to delay list 5. When it runs out, the number is removed from which ever list it is on c) Auto-Answer mode behavior 1. Auto-Answer in 5 seconds if no DIC 2. Get 10 seconds after DIC to enter CIC 3. If 10 seconds times out then no connection is possible 2. Switzerland a) Command/Indication modification 1. Modem must remain on-hook for 5 seconds after disconnect 2. Modem must remain on-hook for 5 minutes after 4 consecutive failed calls 3. If modem must remain on-hook, then it is "paused" 4. If the modem is paused and a call is attempted a PAU indication is given. a) PAUt Modem is paused for t minutes b) Delayed and Forbidden list behavior 1. 2 minute delay between 4 retries 2. After 4 retries the number is put on the forbidden list 3. The number remains on the forbidden list forever c) Auto-Answer behavior 1. Auto-Answer mode after 2 rings if no DIC 3. Austria a) Command/Indication modification (none) b) Delayed and Forbidden list behavior 1. No delay between retries 2. After 2 retries to numbers that answer, but give no answer tone (CFINT), the number is put on the forbidden list 3. After 10 retries with busy or no dialtone, the number is put on the forbidden list 4. The number remains on the forbidden list forever 5. Delayed and Forbidden Numbers lists are checked when dialing in AT mode. If dialing is not possible then NO CARRIER is the response. c) Auto-Answer behavior 1. Auto-Answer in 5 seconds if no DIC 4. France a) Command/Indication modification (none) b) Delay and Forbidden list behavior 1. 2 min. delay after 1st call, 4 after 2nd, 6 after 3rd, etc. 2. After 5 retries, the number is put on the forbidden list 3. The number remains on the forbidden list forever 4. Delayed and Forbidden Numbers lists are checked when dialing in AT command mode. If dialing is not possible then No Carrier is the response. c) Auto-Answer mode behavior 1. Auto-Answer in 5 seconds if no DIC 5. Belgium a) Command/Indication modification (none) b) Delay and Forbidden list behavior 1. 1 min. delay between calls 2. After 4 retries, the number is put on the forbidden list 3. The number remains on the forbidden list for 1 hour after entry to forbidden list 4. Delayed and Forbidden Numbers lists are checked when dialing in AT command mode. If dialing is not possible then No Carrier is the response. c) Auto-Answer behavior 1. Auto-Answer in 5 seconds if no DIC. 6. Singapore a) Command/indication modifications 1. Dialing digit '=' means wait for dialtone (acts the same as ':' in dialing string). b) Delay and Forbidden list behavior 1. 5 retries without delay 2. 2 minute delay between next 4 retries 3. After 9 retries the number is put on the forbidden list 4. 120 minute timer is started on entry to delay list 5. When it runs out, the number is removed from whichever list it is on. Appendix I RS232C Interface Specifications The MT1432BA's RS232C interface circuits have been designed to meet the electrical specifications given in EIA (Electronic Industries Association) RS232C standards. All signals generated by the modem are approximately 10 volts when measured across a load of 3000 ohms or greater. The receiving circuits of the modem will accept signals in the 3 to 25 volt range. The voltage thresholds are: Negative = voltage more negative than 3 volts with respect to signal ground Positive = voltage more positive than +3 volts with respect to signal ground SIGNAL INFORMATION: NEGATIVE POSITIVE Binary State One Zero Signal Condition Mark Space Control and Timing Function Off On The input impedances of all modem circuits which accept signals from the data processing terminal or CPU equipment have DC resistances of 4.7K. For more specific details, consult the EIA RS232C standard itself. The following chart lists the EIA RS232C interface pins and circuits present on the MT1432BA's RS232C Interface connector. All other pins are unused. Pin Designation eia CCITT signal Function assignment circuit circuit source 1 pg -- 101 -- Protective Ground 2 SD BA 103 DTE Transmitted Data 3 RD BB 104 DCE Received Data 4 RTS CA 105 DTE Request to Send 5 CTS CB 106 DCE Clear to Send 6 DSR CC 107 DCE Data Set Ready 7 SG AB 102 -- Signal Ground 8 CD CF 109 DCE Carrier Detect 9** +v +v -- DCE Test Voltage 12 HS -- -- DCE High Speed 15*** TC DB 114 DCE Transmit Clock 17*** RC DD 115 DCE Receive Clock 20 TR**** CD 108/2 DTE Terminal Ready 22 RI CE 125 DCE Ring Indicator 24 XTC DA 113 DTE External Transmit Clock 25 OOS CN 142 DTE Terminal Busy **Pin 9 need not be present in your RS232C cable ***Pins 15 and 17 are necessary only for synchronous operation ****Also known as DTR (Data Terminal Ready) The computer or terminal should be supplied with a cable terminated with a Cinch DB25P (or equivalent) connector mounted in a Cinch DB51226-1 (or equivalent) hood assembly as specified by the EIA RS232C standard. FUNCTIONAL DESCRIPTION OF RS232C SIGNALS: Transmitted Data - Pin 2, SD (BA) Direction: to modem Signals on this circuit are generated by the customer's terminal and transferred to the transmitter of the MT1432BA. A positive signal is a space (binary 0) and a negative signal is a mark (binary 1). The transmitting terminal should hold this line in the marking state when no data is being transmitted, including intervals between characters or words. The TRANSMIT (XMT) LED indicates the status of this circuit. Received Data - Pin 3, RD (BB) Direction: from modem The lead is the data output of the modem. Data signals received from the remote modem are presented on this line. When no carrier signal is being received (pin 8 negative), this line will be forced into a marking condition. The RECEIVE (RCV) LED indicates the status of this signal. Request To Send - Pin 4, RTS (CA) Direction: to modem The RTS signal indicates to the modem that the computer or terminal has data that it wants to transmit. Clear To Send - Pin 5, CTS (CB) Direction: from modem The CTS line indicates to the terminal that the MT1432BA will transmit any data present on the Transmit Data line (pin 2). Data Set Ready - Pin 6, DSR (CC) Direction: from modem DSR On indicates that the MT1432BA is in the data mode and is connected to the communications channel. This signal will be on during analog-loop-test mode. Signal Ground - Pin 7, SG (AB) The SG lead is connected to signal ground of the modem. It establishes the common ground reference for all other interface signals. Data Carrier Detect - Pin 8, CD (CF) Direction: from modem DCD On (positive voltage) indicates that data carrier has been received from the other modem. This circuit will not normally turn on in the presence of message circuit noise or out-of-band signals. There is a one second delay between when the carrier tone has been detected and when the CD circuit is turned on. This signal goes off if received data carrier falls below the receiver threshold for more than 37 mSec. When CD is off, the Received Data circuit (pin 3) is held to the marking state. Test Voltage - Pin 9, XV Direction: from modem The XV lead has 330 ohms of resistance to +12 volts DC. This lead may be used to strap other signals high. For example, if the terminal does not supply a DTR (Data Terminal Ready) signal, Pin 9 may be jumpered to Pin 20 (DTR) on the RS232 connector or in the cable to force DTR on. Transmit Clock - Pin 15, TC (DB) Direction: from modem The TC signal is provided only when the MT1432BA is used in the synchronous mode. The clock is a square wave and is used to provide the computer or terminal with timing information for its Transmit Data circuit (pin 2). This clock will be provided on the interface at all times when the modem is in synchronous mode. The first signal element of the Transmitted Data signal should be presented by the terminal on the first positive (Off to On) transition of TC which occurs after the CTS circuit on pin 5 has turned on. The transmitted data is sampled by the modem on negative transition of TC. Receive Clock - Pin 17, RC (DD) Direction: from modem The RC signal has the same characteristic of Transmit Clock, with the exception that it is used to provide the computer or terminal with timing information for its Receive Data (pin 3) circuit. The negative transition (On to Off) of RC indicates the center of each signal element on the Received Data circuit. Data Terminal Ready - Pin 20, TR or DTR (CD) Direction: to modem This signal (TR or DTR) provides a means for the terminal or computer to control the modem's connection to the communications channel. A high DTR signal is required by the modem to be able to communicate. Turning DTR off for more than 50 mSec will force the modem to disconnect. The most common use of DTR is in automatic answer applications. A high DTR signal is required by the modem to answer a call. A frequently used method is to have the computer turn on DTR in response to RI (Ring Indicator), which allows the modem to answer. Later, DTR is turned off at the conclusion of the log off procedure, which forces the modem to disconnect, enabling it to receive another call. In non auto answer applications it is advisable to leave DTR on using the modem's DIP-switch option. This is the standard factory setting. An alternative is to provide a constant high DTR from the terminal or computer. The Data Terminal Ready (DTR) LED indicates the status of this signal. Ring Indicator - Pin 22, RI (CE) Direction: from modem This signal will remain on for the duration of the ringing signal. When a ring signal is received by the modem, the modem will automatically answer after the first ring. The modem will answer after a specified number of rings which can be programmed in AT Command Mode, but if none is specified, the modem will answer after the first ring. External Transmit Clock - Pin 24, XTC Direction: to modem Supplies the same function as transmit clock on Pin 15. Terminal Busy (Out of Service) - Pin 25, OOS Direction: to modem The Terminal Busy (OOS) circuit is not defined in the RS232C standard, but is used by us and most manufacturers to make the phone lines busy to incoming phone calls. Pin 25 is not normally connected to the RS232C interface when shipped from the factory; it can be ordered connected as an option. If pin 25 is connected and is brought high, the modem will be placed Off Hook, and busy to incoming calls.