1.	Introduction..

	1.1	What is MNetSvr
	1.2	MBAP network extensions for Modbus
	
2.	MNetSvr System Requirements

	2.1	Operational Overview
	2.2	Interaction with MBAP Clients

3.	Installation

	3.1	Making Backups
	3.2	Installing MNetSvr

4.	Basic Operation

	4.1	Setting up the Serial Port
	4.2	Network Connections

5.	MNetSvr Display

	5.1	Event messages
	5.2	Monitoring Serial Data
	
6.	Distribution/Registration

	6.1	Pricing
	6.2 	Licensing
	6.3	Support
	6.4	Other Products



1.	Introduction..

1.1	What is MNetSvr
MNetSvr is a Windows 32-bit application designed to operate as a bridge 
device between serial modbus slave devices and TCP/IP client applications
operating as modbus masters.  The application uses the standard MBAP
protocol as defined by Modicon, to service multiple asynchronous
connections to network clients.  Each client application can issue
commands to MNetSvr, which in-turn, will obtain the results from the 
attached slave and respond to the client.

1.2	MBAP network extensions for Modbus
MBAP, (Modbus Applications Programming Interface), defines the protocol
used by an application to obtain data from a modbus device connected via 
a network.  The MBAP protocol defines a series of header characters,
(prolog), appended to the front of each modbus message to allow transmission
over a multi-drop communications system such as an ethernet TCP/IP network.

	
2.	MNetSvr System Requirements

2.1	Operational Overview
MNetSvr is a Win32 application which requires Windows 95/98 or Windows NT.
At least one serial port must be available for connection to the serial 
modbus device(s), and a network connection must be available for servicing
MBAP client applications.  Windows Sockets and TCP/IP must be installed on
the target machine.

During start-up, MNetSvr will open the MBAP service port, (502), and listen
for connection requests from network clients.  As connections are made, 
MNetSvr will spin off threads of execution to service each connection
independantly.  If no messaging activity occurs on a given connection
within a five minute period, MNetSvr will close the connection to conserve
resources.  This prevents an abnormally terminated client application,
(one which does not gracefully close the connection), from having an
adverse effect on the Server's performance.

2.2	Interaction with MBAP Clients
Operation of MNetSvr after establishment of a network connection is quite
simple.  A client application makes a request for data from a slave device.
The server accepts the request and routes it to the appropriate serial
channel for processing by the slave.  When the results are returned,
MNetSvr formats the data and returns the information to the requesting
client.  Since multiple client connections may be active at any given
time, MNetSvr can effectively distribute data from a single slave device
to multiple modbus masters. 

3.	Installation

3.1	Making Backups
A single-user license for the MNetSvr application provides for its use on 
a single Win32 machine.  All executable and dll files necessary for its
operation are distributed as a shareware/demoware package with various
time limits and registration reminders enabled to encourage registration.
These files may be duplicated and distributed at will.

If a registration payment is made, the user will receive an access code
which must be entered into the MNetSvr sign-on dialog to enable full
functionality of the application.  This will result in the creation of 
a mnetsvr.cfg file containing the registration information.  The
mnetsvr.cfg file generated with a single-user license may only reside
on a single machine.  Paper copies of the access codes may be made and
retained for back-up purposes, however, electronic duplication of the
mnetsvr.cfg file is prohibited.

3.2	Installing MNetSvr
Installation of the MNetSvr application consists simply of copying the
distribution files from the supplied diskette, (or downloaded .zip file),
onto the hard drive of the target PC.  Installation of the supporting
network drivers is defined by the network driver vendor's documentation.
MNetSvr uses the standard WinSock API for network communications, and
may be used with direct network connections as well as PPP dial-up 
connections as supplied by the Win32 operating system.

4.	Basic Operation

4.1	Setting up the Serial Port
A MNetSvr menu command, (File Connect), allows the user to define the
operating characteristics of the PC's COM port.  A dialog box prompts
for information concerning the port number, baud rate, and parity 
selctions, as well as the protocol, (ASCII or RTU), to be used in
communicating with an attached slave device(s).

4.2	Network Connections
Network connections are initiated by MBAP compatible client applications
by requesting a TCP connection to port 502.  The IP address of the PC
hosting the MNetSvr application must be supplied.  This address is available
by observing the MNetSvr Tiltle bar after initiating a serial connection.
If the MNetSvr application resides on the same PC as the client, IP address
127.0.0.1 may be used.

5.	MNetSvr Display

5.1	Event messages
The MNetSvr display window is divided into two parts, (views), separated
by a horizontal splitter control.  The splitter bar is used to adjust the
relative sizes of the two views.

The upper splitter view is used to display network events.  As client
applications connect and disconnect, a message will be added to the
display which details the time and description of the event.

5.2	Monitoring Serial Data
The lower splitter view is used to display the serial data stream as
transmitted to and from a connected slave device.  Each modbus transaction
occurring between the MNetSvr application and a slave device will be
displayed in this view.

6.	Distribution/Registration

6.1	Pricing
MNetSvr is a time-limited demo application which allows you to connect
to serial modbus devices using any MBAP-compatible network application
to evaluate its operation without cost or obligation.  MNetSvr is designed
to allow unrestricted use for a period of 3 1/2 minutes after successful
communication is established with a network client.  Multiple client
applications are supported, with each connection remaining active for
the 3 1/2 min evaluation period.  After the demo time expires, the Server
will drop the connection and the client must re-establish the link to 
resume operation.

Registration of the MNetSvr application removes all time-limits and allows
unrestricted network access to connected slave devices.  The introductory
registration price for the MNetSvr application is $89.95, and provides a
single-user license for operation on a single Windows Machine.
Multi-machine and Site-Licenses are available.

For the latest pricing and availability details, please refer to the
WinTECH Software Web-Site at 
http://www.win-tech.com

6.2 	Licensing
MNetSvr is distributed as a shareware/demo-ware application which may
be freely distributed without charge to prospective users.  Time limits
and registration reminder screens are utilized to encourage registration.
If you find this application useful, please refer it to your associates
in the hope that they too may be able to use it.

If you choose to register this application, you will receive a license
certificate with access codes which will remove all program restrictions
when entered into the initial sign-on dialog box.  You will only need to
enter the registration codes once.  A single-user license allows the
purchaser to use the application on a single machine.  Running multiple
instances of the application on different machines at the same time is
a violation of the copyright owned by WinTECH Software.   Multiple-User
and Site-licenses are available for installations which require multiple
simultaneous use of the MNetSvr application.

6.3	Support
For the latest product and pricing information, please refer to the
WinTECH Software Web-Site at:

http://www.win-tech.com


For technical support, please e-mail:   
support@win-tech.com

To place an order, fax to:  
1-304-645-5966

or mail:	
WinTECH Software
P.O. Box 907
Lewisburg, WV  24901
U.S.A.

6.4	Other Products
WinTECH Software offers the following products and services which may
be of interest:

Modbus Driver Dlls
	Windows drivers are available to support either the modbus master
	or modbus slave protocol on a PC.  These drivers are written in C.
	They are available in either 16 or 32-bit designs and include all
	modbus message formatting and interaction with the Windows serial
	drivers.  A simple API is made available to your application, which
	greatly simplifies its design and allows you to very easily implement
	a custom modbus design under Windows.  Each driver is very reasonably
	priced, and comes with a sample Windows application written in the
	Microsoft MFC.  Expanded versions of each driver is available which
	support network and modem, (TAPI), connections as well as direct
	serial connections.

ModScan32 Windows Application
	The ModScan application operates as a MODBUS mastermodbus_protocol
	device in either RTU or ASCII transmission modes.  ModScan may be
	used to access and modify data points contained in one or more
	MODBUS slave devices connected to the PC via a serial port, modem,
	or network.  ModScan supports the standard MODBUS message types 01-06,
	15 & 16, as well as providing the ability for you to exercise
	special features of a slave device by transmitting custom command
	strings and observing the response.  ModScan is a useful test and
	diagnostic tool for verifying the proper slave response to MODBUS
	queries as well as being a low cost data collection tool for
	interfacing data into PC database and spreadsheet applications.

ModSim Windows Application
	ModSim is the counterpart to ModScan and simulates the slave end
	of the modbus protocol.  ModSim allows you to define a series of
	data points, (representing one or more slave devices), and provides
	this data to an attached modbus master application.

Listen Windows Application
	Listen is a fully functional serial data link monitor, (datascope),
	which allows you to watch data traffic in real time as it travels
	in two directions between communicating devices.  Listen is highly
	customizable in the way it displays data and uses standard COM
	drivers for compatibility with any serial hardware configurable
	under Windows.

Socket Spy Windows Application
	The Socket Spy allows you to monitor TCP/IP packets transferred
	between a Windows application and the Windows Sockets dll.  Designed
	as a design and trouble-shooting aide for communications developers,
	Socket Spy provides full debugging data relative to all sockets
	activity occurring within the target application. 




