AB Ethernet - Pass commands between PLCs? Logix500

Hello,


I have two ML1400 PLCs which share some I/O duty (i.e. I am using outputs on both PLCS to drive a bank of solenoid valves (1-6 on PLC 1 and 7-10 on PLC2).

I know how to use the MSG block R/W, but was hoping I could just address PLC2 directly in PLC1, making PLC1 contain the "main" program, so when I write an output in PLC1's program, it can drive that output on PLC2.

If I can't discretely address, then I'll have to bulk-transfer address/values via the MSG function, otherwise, I'd have to write two portions of the code to both PLCs, which seems like a mess to me.

Thanks for your help.

Tim

Can try using the MSG write command to write the output command in PLC1 direct to PLC2 so that PLC2 act as remote I/O.

MicroLogix controllers aren't made to run remote I/O like ControlLogix are. Unless there is no other way, I never recommend using MSG instruction logic to perform I/O control functions.

The MicroLogix 1400 supports up to seven 1762-family I/O modules. Are you already maxed out ?