Modbus Communications - trip units


Thread Starter

Chris Kellock

I'm trying to find anyone who has used the GE Modbus Concentrator for trip units before. I've got a Modbus/Modbus Plus/Ethernet network. Our Modicon Quantum PLC is set up for hot standby. Since the system can't move IP addresses from NOE to NOE after the hot standby switchover, we put in a Modbus Plus to Ethernet gateway. Now the MB+ port on the CPU is used for communications. We go thru the first bridge to get to ethernet, and then come back through a Modbus to Ethernet bridge to Modbus to talk to the GE unit and some Multilin devices. I can talk to the Multilin devices, so I know the routing addresses are correct and both bridges are working. I can get data from the GE concentrator, but not from any of the devices attached to it. Any ideas?

Sam Meshulam

Dear Chris,

I have experience and expertise in this area since I defined Modbus Plus and all associated products including the ethernet gateway when I was at Modicon, some years ago.

I am a consultant, so maybe able to assist.

email address is [email protected]
you need to set up the modbus concentrator to see your trip devices attached to each leg (A through H). you can do this manually from the modbus concentrator front panel or by using the modbus concentrator software (it think it is called modproxy). Using modproxy you can set this up automatically via a laptop or PC connected to the modbus concentrator. The software searches each leg for any commnet protocol devices (such as mvtpm or mvt plus units). Good Luck. [email protected]