Leidy.utt

Hello :)

Recently I have beeing working with the module CM1241 with a S7 1200.

I have made the communication and I don´t have any errors, the problem is that when I try to send a value, it doesn´t change.

I have put the adress 0 because send the values for all slaves that I have, and if I change the adress, BUSSY change to 1 like the PLC was searching an slave.

I have tried change the adress for 2 or 4 but "bussy" is always 1  please Help!!!

There are some pictures.

Hello.

I strongly suggest you make sure the link to at least one slave is working. Then continue to push onto the broadcasting. MB_Master is not the newest Modbus RTU commands. Look for Modbus_Master.

The manual states the following on a description of the Modbus address parameter in the Modbus_Master instruction:

MB_ADDR
The value of 0 is reserved for broadcasting a message to all Modbus
slaves. Modbus function codes 05, 06, 15 and 16 are the only function
codes supported for broadcast.

See the table attached for details on the function codes and which register addresses can be linked to.

Not further that the register address in your code segment links to 4,001. I think 40,001 is expected.

Thanks a lot for your support.

I have made the configuration and I can read and write registers.

My computer can´t read and write so I put a router to help it and it was all, after that the router made it job all was working.

Kaulquappe

Hello,
the first thing you should do: evaluate the outputs of MB_MASTER in your program:

How do you evaluate the status of system blocks in STEP 7 (TIA Portal)?

Regards,
Kaulquappe

Thanks a lot for your support.

I have made the configuration and I can read and write registers.

My computer can´t read and write so I put a router to help it and it was all, after that the router made it job all was working.