Is put/get necessary for communication between 2 PLCs?

[plcnoob69]

Or there is an alternative to this? I suppose there are many but I've only seen put/get
Can you for example set up a new plc and connect it to an existing scalance or profibus node, and have both PLCs read the same inputs? Or for example have one PLC raise outputs as signals to the other PLC?

 

[Old Man]

Modbus?

 

[Rob...]

SIOS

support.industry.siemens.com

Might want to check this out.

 

[cardosocea]

You can, and should consider, multicasting when you have a large number of controllers as well.

Also, if you use PUT/GET, you must have some sort of heartbeat to detect if the other end is actually processing logic or simply turned on but in stop mode.

 

[mk42]

What is your PLC and FW and SW version?

Current Siemens PLCs support controller to controller comms as IO: I-Slave on Profibus, IDevice on Profinet. As you suggest, it maps IO memory in one PLC directly to IO memory in another PLC.

There is also a feature for multiple PLCs to read the same inputs from an IO rack, called MIMO, I think? It requires the IO device to support it, and not many do.

 

[JesperMP]

What is possible depends entirely on the PLCs in question.
What is recommendable depends on the application.