Modbus TCP/IP simulator

[fersra 0]

Hello, I am new in Modbus and in this forum so sorry if I am posting this in the wrong place. I would like to create an scenario (first simulate and then with real PLCs) with several masters connected to a several slaves where I am able to test the communication each other with Modbus TCP. It should be necessary work with redundant networks where every device should have 2 ethernet ports (with differents IP's) in order to get availability. I have seen a lot of programs on internet but I don't know if there is a useful tool with client and server functions to test communication, with ability of communicating with multiple master and slaves and work with redundant networks (I don't know if this is possible). I don't mind if the program is not freeware. Do you suggest anything? If you don't know any with the ability of work with redundant networks, could you recommend me the best simulator in your opinion? I have tried SimplyModbus and Modbus Poll from modbustools.com so far. By now, I prefer the last one. Thanks. Edited 11 Jul 2013 by fersra

[kaare_t 155]

I prefer Modscan32 (master/server) and Modsim32 (slave/client) from WinTech (http://www.win-tech.com/). They are very minimalistic and easy to use. However your question about redundancy is a bit hard. I doubt you will be able to have redundancy all the way into your computer. The most normal way to use redundancy is to have redundant ring switches, with one patch cable from a switch to a device (in other words; your peripheral devices connect to a switch with one cable only, but the ring switches connects in a ring using two cables for redundancy).

[Kaviarasan 0]

You can try Modbus protocol tester (master) which is free for download from here:http://www.colwaysolutions.com/modbus-protocol-tester.php

 

For a slave, you can find a Modbus RTU and TCP slave implementation in 'C' source code form at http://www.colwaysolutions.com.

 

Since the implementation is in ANSI 'C' you can port it easily to any controller. 

**Slave supports following 11 function codes.

Read Coils(0x01),

Read Discrete Input(0x02),

Read Holding register(0x03),

Read Input register(0x04),

write single coil(0x05),

write multiple coils(0x0F),

write multiple registers(0x10),

write single register(0x06),

Read exception status(0x07),

Report slave ID(0x11),

Read/write multiple registers(0x17)**

 

The vendor also provides ports to a few popular microcontroller cores like 8051, ARM, Coldfire, Analog devices, Microchip, etc. 

 

Including for some RTOS kernels (OS9, MQX, UC-OS). The library is very lightweight consuming negligible RAM and ROM space.

A slave is not free but the pricing seems to be low. They also provide porting services for getting library ported to your board and working at minimal cost.

 

 

Using Modbus Protocol tester (master) and WIN32(C source code) Modbus slave, you can establish client/server Modbus communication between two different PCs.