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I want to communicate between Tricon PLC and Siemens S5 PLC using Modbus TCP/IP protocol. The Tricon PLC supports Standard Modbus TCP/Ip protocol which can be configured as a master or a slave. But when approached the siemens vendor, I was told i needed a siemens communication module, sub-interface module and a specific modbus driver. And i was told that they don't have a specific modbus driver for tricon PLC. Kindly suggest on how to communicate between these 2 PLC's.

this is a common challenge in automation world usually solved by using OPC. have you tried that option yet?
here is some info to learn about it:
http://www.matrikonopc.com/resources/opc-tutorials.aspx

Wassim Daoud
Global Solutions Architect
MatrikonOPC

hello

i do not think that You need a special communication, no triconex. if You got the siemens interface module which can talk modbus and TRICNEX can do that as well. so they should communicate provided that You configure the right parameters. Which card are you using from TRICONEX EICM? or another card.

Hi,

Thanks for the reply. Im currently using Simatic S5 133U and want to communicate with Tricon PLC via Triconex TCM card. Hence i placed an order for CP524 and a sub-interface module for RS-485 connection. But when requested for a standard modbus RTU driver, I was told that there was only specific driver modbus programs for different vendors. How could this be possible as i understand siemens must have a standard Modbus rtu protol driver? Does S5 133u PLC support a CP which supports Modbus TCP/IP?

> I was told i needed a siemens communication module, sub-interface module and a specific modbus driver. <

Exactly which modules did your Siemens rep say that you needed?

> And i was told that they don't have a specific modbus driver for tricon PLC. <

This doesn't sound right: Modbus is Modbus - Modbus drivers should not need to be specifically crafted to communicate to another piece of Modbus-capable equipment. If you have a Modbus driver for the S5 (Modbus slave, let's say), then your Tricon PLC's Modbus TCP master driver should be able to communicate to it no problem. Registers are registers, no matter the type of equipment they reside on.

OPC would only be an option if you're willing to have a fulltime PC in the mix in addition to your PLC's. If your PLC's both already have the capability to communicate to an OPC client (via Modbus TCP, for example), then there's no reason you can just have them talk to each other via Modbus TCP.

Darrin Hansen

> Exactly which modules did your Siemens rep say that you needed? <

Hi Darrin,

Im currently using Simatic S5 133U and want to communicate with Tricon PLC via Triconex TCM card. Hence i placed an order for CP524 and a sub-interface module for RS-485 connection.

> This doesn't sound right: Modbus is Modbus - Modbus drivers should not need to be specifically crafted to communicate to another piece of Modbus-capable equipment. If you have a Modbus driver for the S5 (Modbus slave, let's say), then your Tricon PLC's Modbus TCP master driver should be able to communicate to it no problem. Registers are registers, no matter the type of equipment they reside on. <

But when requested for a standard modbus RTU driver, I was told that there was only specific driver modbus programs for different vendors. How could this be possible as i understand siemens must have a standard Modbus rtu protol driver?

Unfortunately there is no dedicated PC in between these 2 PLC's and hence OPC is not an option.

I suspect that the problem is most likely in the Siemens computer ordering system rather than in the protocol. It is quite possible that they list protocols as "Allen Bradley DF1", "Modicon Modbus", "Omron FINS", etc. The person at the vendor handling the order entry may not know anything about Modbus, or indeed anything about a CP524. When you tell them that you just want "Modbus/RTU", the person handling the order doesn't know what button to push because there isn't a button labeled "Triconex".

Someone at Siemens will know something about the CP524 and about what the correct driver is. The problem will be getting through to that someone. Siemens will have a rep handling your area. I'm talking about an actual Siemens employee, not your vendor's sales staff. That rep will in turn have other contacts inside Siemens. He can get the answer (the part number) for you if you can get in touch with him. You can then give the part number to your distributor to place your order.