Control Net

Greetings,

Quick Control Net question. I don't work with it much, but inherited a network on an OEM piece of equipment.

There are two Control Logix racks. Rack 1 has a processor and a CNB card (and I/O0. Rack 2 only has a CNB card (and I/O), no processor.

My question is if the two racks lose communication, will the outputs on the remote rack with NO processor shut off? I know you can configure the output card how to act on a fault etc.., but what happens if there is no processor in that rack?

TIA,

Greg

The I/O cards get their communication fault behavior configuration information when the controller establishes the connection to them over the network. You'll see this in RSLogix 5000 in the module configuration window, on the "Configuration" or "Output State" tab.

If the connection fails because of a failure of the controller, the first bridge module, the network, or the second bridge module, then the I/O module will take the action configured in that tab.

If the power is cycled to the chassis but a Connection is never made to the controller, then the modules will remain unconfigured and outputs will remain off.

Thanks for clarifying Ken. I have the outputs configured to be "off" in both program and fault mode cases. Just wasn't sure if the I/O had the closed loop communication check back to the processor in the main rack to shut off in this case where there is no processor in the remote rack.

Greg