Good day everyone,

Please, i need some information about PLC communication. I saw some siemens examples, but in this project only one PLC have a GET/PUT programm. As i understand for communication beetwen two PLC we need write GET/PUT programm on both of them? That's right? 

Hello Alexandr;

PUT and GET functions establish a client-server connection between 2 CPUs, with an unspecified partner.The connection can be established over MPI, Profibus or Ethernet links.

That means that you can setup the connection in one CPU, the client, insert the PUT and GET functions in the client's program, and the server will simply accept the data transfer requests from the client.

Nothing forbids you to setup PUT and Get fiunctions on the other CPU if you need to. It will simly act as client to the other CPU (acting as a server) over the unspecified connection that you will setup on that client CPU.

Generally, if you have enough of the 160 bytes limit for PUT and GET fnctions, then choose one CPU as client, the other one as server, and setup all required configurations on the client.

Hope this helps,

Daniel Chartier

Thats really helpful. Thank you.

Another one question about network configuration. For client i need enable "Active connection option" in Configure Network? And what ID I need use in GET in PUT? My client ID (PLC with PUT/GET programm)  in PUT and GET block. Or different ID depending on the PUT data or GET data?

Really sorry for my silly questions :)

PS. Both PLC in one project (specified S7 connection).

hi alxndrch,

when you establish a connection the connection got an ID.

By using the PUT and GET-blocks, the blocks need to know which connection to use. with the parameter ID the blocks get the information which connection they should use to put and get data.

here you find an application sample for PUT/GET-communication with S7-300:

How do you program communication blocks FB14 "GET" and FB15 "PUT" for data exchange in the S7 program of an S7-300 CPU?

hope this helps,

regards,

Thank you for you answer.

I saw this examle. In accordance with it i configure my PLCs. On my first PLC1 (Local ID 1) I create new connection with second PLC2 (Local ID 1, Parther ID 2) and active connection partner = YES

On PLC2 automaticaly created new connection (Local ID 2, Parther ID 1 and active connection partner = NO)

I create my PUT/GET programm on PLC1, and using ID 1 for PUT and GET blocks. PUT and GET blocks have no error on monitor mode, but DB for recieve (on PLC1) didn't uptate with new value from DB for send (on PLC2).

I will continue to try.

hi alxndrch,

error and status are only valid for one cycle. If you don´t get a DONE-bit or NDR-bit the ERROR-bit is true for one cycle. If it comes you need to save the STATUS-word, like this:

In Step7-help or TIA-help of the PUT/GET-blocks you will find the meaning of the STATUS-value.

hope this helps,

regards,

Thanks for all answers, it's really help! But...

Currently I don't have a real PLC, so I'm using PLCSim. But communication didn't working. I try Siemens S-400 example and have no problems with it, communication work. But S-300, I realy dont't know what problem with my project. For project i use that application note:

https://support.industry.siemens.com/cs/de/en/view/18610307

Project in the attachment.

On real PLC communication works.