Modbus RTU and CM PtP (No led blinking)

Hello everyone,

CPU : CPU 1512SP-1 PN

CM PtP : 6ES7137-6AA01-0BA0

19200 bits/s, No parity, 8 bits, One stop

I'm using Tia Portal v17 with MODBUS RTU in 5.0 and CPU in 2.9.

So, I try since many day to operate my CM PtP with a station, I have no error code, only status code (16#7000, #7001, #7002), I have no Tx or Rx led blinking. All the stuff is well configured but no communication is made.

I don't know what I have to do to operate this.

You have the pictures of my program below.

Thanks.

Swarley92

Hi ExOWiiZz!

Have you tried using an error logic to identify if the error is not being overwritten? Perhaps it helps. You can find more information on this link.

 Hi Swarley92,

Thanks for your answer,

I try your solution, I now have the error code 16#80C8, that mean "The slave does not answer", so I review all the communication information (baud,parity,etc...), I reverse the wiring, try many possibilites and still the same error code.

Do you have any solution for me ?

Have a good day :)

Hi ExOWiiZz,

If I am not wrong, in that CM PtP module Tx and Rx cable connection are swapped. Try to cross the cables and see what happend.

I would also check MODE static parameter, it should have value 4 as you are using RS485 protocol.

Hope it helps.

Br,

Cocolino

Cocolino

Hi ExOWiiZz,

If I am not wrong, in that CM PtP module Tx and Rx cable connection are swapped. Try to cross the cables and see what happend.

I would also check MODE static parameter, it should have value 4 as you are using RS485 protocol.

Hope it helps.

Br,

Cocolino

 Hi Cocolino,

Thanks you very much for your answer, I know have the RX Led blinking on my gaz detection unit this is already an accomplishment, but the error code is always here (16#80C8), I try to inverse the wire but nothing.

Do you have any idea ?

Thanks

 Happy to hear that.

Thanks for share the solution,

Br