OPC in a s7 it-module

[JVL.]

Hai, We have to connect a cpu to a scada system by OPC. Normaly we connect the plc by tcp/ip to a PC. On the PC runs a opc master or slave. The PC is connected to a other PC with the scada system. We like to cancel the first PC and connect the cpu direct to the second pc. Therefor we need a OPC in the PLC-system. Is it possible to run a OPC on a communication card such as the CP341? Thanx for your reactions JVL.

[Crossbow]

Not that I'm aware of. You need a PC to run the software. Why not just run the OPC server on the second PC? I guess I'm not following what you are trying to do.

[JesperMP]

It is not clear how you used to do it before. Did you set up the OPC server on one PC, and then you connected the other PCs OPC client via DCOM ? That would be possible but just a little bit cumbersome. To install the OPC server on the same PC as the OPC client software (the scada package) would be simpler (and more 'normal'). edit: Just to make it absolutely clear. You cannot run an OPC server in the CP341 IT module. Edited October 10, 2005 by JesperMP

[JVL.]

The normal way is: plc > opc on the vendor pc. only we have to make a line between the s7 part and the vendors part. therefor we use a second pc. My question is: is there a opc server or client with runs on a cp-card in the s7 rack? JVL.

[Crossbow]

As we stated earlier, the CP card is NOT a PC. It can't run PC software. There is no way to put an OPC server on a module in the S7-300 rack. I still don't understand why you can't load the Siemens OPC on the vendor's computer? Why are you looking to insert another computer in the system? There are some OPC servers that can talk to each other, so you might be able to do what you ask by putting another PC in to handle the comms to the S7, and then have their OPC polling yours. I've never done this, I've always had one PC with the OPC packages on it for the SCADA system. Typically it's the same PC that runs the SCADA package.

[JesperMP]

Nothing stops you from putting an OPC server on the PC with the SCADA software. You have then achived what you want. If I understand you correctly, then you normally connect to various vendors via an intermediary PC - maybe using DCOM to achieve that. This is an unnecessarily complicated setup.