Implementation of Modbus TCP/IP between two PLCs

Hello!

Can somebody help us? We have two Siemens S7 PLCs and we want to implement Modbus TCP/IP between thoose two, but we also need to implement Profibus from one of the PLCs to a laptop with LabVIEW. And we must program the PLC between Modbus TCP/IP and Profibus in SCL-language. Any suggestions?

Best regards,
Tony

You want to use Modbus/TCP between two Siemens PLCs, and Profibus from a Siemens PLC to Labview on a PC? And you have to program this in SCL? That sounds like doing things the hardest way possible. Is this supposed to be a special challenge?

I haven't tried that (nor can I recommend it). It might be a lot easier to use Profibus between the PLCs, and Modbus/TCP to the PC.

A quick search on Google turns up Modbus/TCP for the S7-300, and Modbus/TCP for Labview. Have a look on Google for "S7 Modbus TCP" for more links. You will find that about half the top rated links go back to pages on this forum. I suggest that you read those as well.

http://www.industry.siemens.com/IT4Industry/en/solution_services/simatic_addons/proto_mod.htm

http://sine.ni.com/nips/cds/view/p/lang/en/nid/201711

Tony, This post might help you with the Modbus TCP in S7: http://forums.mrplc.com/index.php?showtopic=12162

Depending on the version of LabVIEW (8.0 and up), Labview has a built in Modbus I/O Server (master or slave) with shared variables and you do *not* need the DSC toolkit.

To get LabVIEW talking on Profibus see this link: http://sine.ni.com/nilex/DisplayLinkAction.do?id=12184EXT

David

Hi there,

I would suspect that the easiest way to solve it, is to use a gateway Profibus slave to Modbus TCP slave. For more information, go to:
http://www.anybus.com/support/support.asp?PID=244&ProdType=Anybus X-gateway
or email me at: [email protected]

/Pat