Communication cFP and profibus PLC

[tengels]

I have some questions concerning Profibus communication between a Compact Field Point system and a Siemens PLC.

The following hardware is used:

NI cFP 2120 controller

Siemens S7 314 MPI

Has somebody tried to read data from a Siemens PLC over the RS485 ports with profibus?

If yes, could we get the (Siemens) command set so we can try to retrieve data from the PLC (using NI-VISA).

Or has somebody already programmed a solution, could we then have an example of how it has been programmed.

Has somebody solved this problem of communication in a different way? What was the solution and how much time / money did it take.

Hope someone could help me with this problem.

Already thanks for the effort.

[Aurora]

Hi

You may want to consider using a hardware gateway to do this. The following link could be a start - http://www.ni.com/comm/third_party.htm. I see you're using 7.1 so you could possibly use the Modbus library VIs available for LV to communicate with a gateway that will in turn access the PLC data. LV 8.0 and newer allows you to enable a Modbus IO server using the shared variable engine. This would make programming simpler.

I've not tried this myself, but this is an option I'm exploring as well.

Later

[S59X]

Hi!

I haven't used cFP yet, but I have succesfully connected PCs to Siemens S7/S5 PLCs. I use two methotds. First involvs calling functions from Prodave MPI DLL. Prodave MPI is an API product from Siemens. That of course won't run on cFP.

The second method uses MPI/Ethernet converters. I that case you need to send commands to MPI/Ethernet converter over TCP/IP. I think this should work on cFP also. I use the MPI/Ehternet converter from IBHsoftec (http://www.s5w.business.t-online.de/english/Selection_Hardware_S7.htm), for which I can send you the VIs I use.

This is all MPI protocol, not ProfibusDP.

Mirko