AB Ethernet - Pass commands between PLCs? Logix500

[TimD]

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

 

[allentcm]

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.

 

[Eddie Willers]

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 ?