Opereator Interface

[Guest Solonas]

I have 90-70 plc with cgr772, ccm711 I have 2 datapanels (DP 150) and i want to connect them to the CMM711 module using SNP/SNPx. I've made the wiring for parallel connection but only one datapanel -at a time- can access plc's data. (When i remove the one edge, the other dp communicates) Does model 150 support parallel connection to other datapanels or should i exchange it with 160/240? I've configured both datapanels to use protocol 68(snp/snpx) and RS485 (4wire) The same configuration is made in cmm711.

[Steve Bailey 118]

The SNP protocol is strictly a master-slave protocol. The Datapanel has the role of master. There can be multiple slaves, but only one master on the SNP multi-drop network. If you want multiple Datapanels communicating with a single PLC using SNP, you will need multiple serial ports on the PLC and a cable for each port. For multiple Datapanels communicating with a single PLC over a single cable, you will need to go to something like Genius or DeviceNet. I'm not sure which (if any)Datapanel models have Genius or DeviceNet daughterboards available. Maybe Russ B will see this thread and clarify what's available. Otherwise, talk to your local distributor.

[Guest Guest_Russ]

Steve is correct. You do have a couple of options, using the hardware that you have. 1. Use the ports on the CPU, assigning one to each DP150. You will need to assign each a different SNP ID. 2. By using the RTU or CCM protocol you can give each port on the CMM711 one DP150. 3. Each DP150 has two ports and holds two protocols. You could 'Daisy-chain' the DP150s into one SNP port. This will slow them down as the first will need to re-send all information to the second and translate the native protocol to SNP for the second.

[Guest Solonas]

Is there any other protocol that could do the job?

[Steve Bailey 118]

The CCM protocol supports peer-to-peer communications. The CMM711 be configured as CCM peer-to-peer, but I don't know if the DataPanel impementation of CCM can be configured as peer-to-peer. It may be limited to master. Be aware that if you use the CCM protocol you can only directly read from/write to %I, %Q, and %R memory areas in the 90-70.