CVI Client communicates with PLC (Siemens) via Modbus

[RTM]

I am think of linking an existing CVI programm running on a PC to a siemens PLC using the modbus protocol.

- Has anybody experience with such an application?
- Any idea about the time effort required to implement such an communication solution with/without the NI OPC server?
- Any examples or code available? - If we could buy some standard code/modules the solves the problem or that may be adabted we'll probably do that.

Thanks for your help - it's much appreciated!

[RobertoBozzolo]

We successfully integrated communication to a S7 plc via rs232 in an application of ours.
If this is your case, I can send you some source code (you'll have to adapt it to your needs and to the messages effectively interchanged with your actual plc). Just let me know.

Roberto Bozzolo

[RTM]

Hi Roberto

thanks for your answer. I'm still waiting to get the specs of the PLC - if it's the right one I certainly appreciate if you could send me the code.

Meanwhile, I wonder

- how long did it take you to implement your solution (ca.)?
- did you use the NI Industrial Automation OPC Server?

Thanks for your answers!

Regards Reto Meili reto.meili@msemeili.ch

[Amit Kumar]

Hi Roberto,

I am also trying to access PLC S7 200 through NI CVI 5.5. I am having NI OPC Server.

I understand that u have done it successfully. Can i have the procedure or some .c codes for doing this.

regards,

Amit Kumar
Project Engineer
AED, ARAI
Pune, India.
amit.aed@araiindia.com