I have some background in PLC programming but I am a begginer with Siemens. I have 2 S7 315-2D. I want to connect them on a Profibus (One master one slave).

My first problem is that I can't make the configuration write. Either BF led (Bus failure) is flashing or BF is off but program goes to Stop when try to run it (OB1 only has the simplest network one input makes one output).

Second what functions can I use to exchange data between the 2 CPU's?
Thanks a lot!!!

 

Hi

Firstly you need to configure the hardware in the hardware configuration tool of the simatic manager. Ensure that both CPU's are connected to the same DP network and that one is master and the other slave. If you do this and download to the CPU's you should get the CPU's into run. There are a number of options for transferring data between them, the simplest is via periperal I/O, again this is set up in the hardware config. In the PLC you only then have to to transfer and load to these I/O areas.

Andrew

 

Thanks a lot. It worked.