Communication between GE PLCs

I have a network of 7 GE Fanuc 90-30 PLCs with 350 CPUs and CMM321 ethernet interfaces. Each ethernet interface is connected to an N-Tron 508 FX-2, and the N-Trons are connected to each other with fiber optic cable. Two HMIs running Wonderware are also connected to this LAN with an N-Tron.

Currently, communication between PLCs is performed using conditional scripts executed by the Wonderware viewer. For example, when a tank level is high, a bit %M00007 is set in PLC 5. Wonderware runs a conditional script to set tagnames PLC3_M00002 and PLC4_M00034 to 1, and these are written to PLC3 %M00002 and PLC4 %M00034, respectively. Each of these bits (PLC3 %M00002 and PLC4 %M00034) are included as normally closed contacts that prevent the transfer pumps in areas 3 and 4 from running when they are set.

I'd prefer to communicate the applicable bits (30 or so total) directly between PLCs instead of going through the HMI. Is there a simple way to do this?

PLCs are programmed in VersaPro.

thanks for any suggestions.

Is there a simple way to do this?

Click to expand...

Simple, no; possible, yes.

Since your CMM321 modules don't support Ethernet Global Data, you will have to use COMMREQ instructions to establish channels among the seven PLCs. This is covered in the manual GFK-1541B, available from their website.

Start here http://globalcare.gefanuc.com/
and then click on "Product Manuals (no login required)"

Be warned that setting up and troubleshooting COMMREQ commands is not a task to be undertaken lightly nor by the faint of heart.