PLC to PLC communication

[bgottenmusic]

Hello, I am new to this forum. I was looking to see if anyone had any info on what I'm trying to do, and I haven't found any, so here is what I am trying to do:

 

I would have 4 PLC's connected to cellular modems at different sites. I would need the PLC's to communicate (transmit and receive) data to each other, but also they need to be gable to communicate back to a station that sites in the middle. That middle station can send and receive to the PLC's as well.

 

The first thing I would ask is is this possible, without having it attached to a SCADA system, and if so, where would I start?

 

Thank

[s.pratt]

Hello,

 

Are you trying to have the PLCs remotely communicate to eachother via the cellular modem?

 

If you, once you connect the modem to the GPRS network (assuming you are using a GSM modem) you may communicate with the Modbus protocol.  I have added the program here: http://forum.unitronics.com/index.php?/files/file/46-modbus-client-and-server-over-gprs/

 

Hope this helps.