connecting s7-1200 plc to Arduino by Modbus RTU

[smsebnaa]

Was this link supposed to be to a manual? for me it just shows a list of support pages with nothing in the search fields.

check this link:
https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&lang=en&objid=36932465&caller=view

 

[smsebnaa]

I have another question;
s7-1200 program works well, but there is a problem after 40 days!
modbus(rtu) communication is freezed and there are not any respond from slaves(arduino).
what is the problem?

 

[KalleOlsen]

...
what is the problem?

That's a good question.


First you must find out if the PLC or the Arduino has frozen.

Kalle

 

[smsebnaa]

That's a good question.


First you must find out if the PLC or the Arduino has frozen.

Kalle

you should be patient until 40 days later!
maybe the solution resistors at end of bus?