Ge 90-30 Communications

A customer of ours has requested two GE 90-30 plcs to be connected together using cmm311 communications co-processor cards. The last time any GE PLCS were connected together we used the Genius communication modules. Does any one have any experience with the cmm cards? Reading the manual it seems that the actual communication tasks are instigated from the Ladder software. Is this the case or does the panel know of an easier way given that we have two cards with the same protocol.

I agree that it would be easier with Genius communications.

To use the CMM311 card, configure one of the ports on the card as an SNP master in one PLC, as an SNP slave in the other PLC. In the PLC with the SNP master, you will need to add ladder logic to control the reading and writing of the data to be exchanged. You won't need any logic in the slave PLC to receive the data, but you may need logic to put the exchanged data in consecutive memory addresses (just as you might have done when using Genius).

Any idea where I could find some sample code for this card?

Chapter 6 of GFK-0582 (Series 90 Serial Communications Manual) includes sample ladder that reads the value of %R101 in the SNP slave and puts the data into %R102 in the master.