Question regarding CPU configured on 2 MPI networks

 Please my CPU configured on 2 MPI network 

Frist on 1.5 MB and running with HMi (selected one) 

Second one on 187.5 KB but it not used.. 

If l set MPI adapter on 187.5  can l exchange with PC? 

dchartier

Hello jagan;

MPI baud rates depend on how the protocol has been implemented on the specific hardware used.

On S7 PLCs, it is required to use 187,5 KB for MPI exchanges. This is how the interfacee in the CPU is set up.

However, with certain Siemens panels that accept MPI, you have the choice of 19,2 or 187,5 kB MPI connections between the panel and the PLC.

The first time I used MPI on a CNC machine, I did not know that the CNC's MPI interface was set at 1,5 MB by default, and when I attempted connection at 187,5 KB as I was used to, I tripped the communication buson the CNC controler, opening all the relays in the control panel at the same time, which brought the kind of surprised and critical looks you never want to see on site.

So your PC Adapter can be used at different speeds for different equipment, but for S7 CPUs you must select 187,5 kB. Just make sure youread the communication section in the product manuals before you select the bus speed fpor your MPI connection.

Hope this helps,

Daniel Chartier

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Split from MPI Baud Rate.

Hello kemo;

To understand your situation, we would need to see your communication configuration, and know details of the CPU and programming software you are using. Screenshots of your HWConfig and Netpro would be helpful (if working with Step 7 v5.x).

But, in theory, since there is only one MPI interface on any given S7-300 or S7-400 CPU, you cannot operate it at two comm speeds simultaneously. That means that if you want to connect to the CPU fron Step 7 you should shut down communications to your HMI @ 1,5 MB, change the CPU properties/MPI to 187,5 kB, compile and download the hardware configuration, probably also adjust your PG/PC interface before you can connect from your programming PC.

Hope this helps,

Daniel Chartier 

Hello,

Thank you DChartier. It seems a lot of helpful for me also!

Regards

OmKris