PLC Gremlin
Member
Hey All,
Im having a difficult time understanding the communication command
on the setup screen of the MSG Instruction.
I have 6 MicroLogix 1500's and a PV on a DH-485 network.
What I do not understand is the 500CPUWrite vs. the 500CPURead .
From the posts I have read and other literature, it seems that you have to program a Write Instrction in one PLC(Node1) and if your sending data to (Node2) then you have to program a Read Instruction in that PLC....
I done some testing yesterday and triggered my MSG in PLC1 to send data to Node 2 (PLC2). I do not have a MSG Read instruction set up in PLC2. When I went online with PLC 2, the word data that I sent was there. SO my question is , What is the Read command for?
Im having a difficult time understanding the communication command
on the setup screen of the MSG Instruction.
I have 6 MicroLogix 1500's and a PV on a DH-485 network.
What I do not understand is the 500CPUWrite vs. the 500CPURead .
From the posts I have read and other literature, it seems that you have to program a Write Instrction in one PLC(Node1) and if your sending data to (Node2) then you have to program a Read Instruction in that PLC....
I done some testing yesterday and triggered my MSG in PLC1 to send data to Node 2 (PLC2). I do not have a MSG Read instruction set up in PLC2. When I went online with PLC 2, the word data that I sent was there. SO my question is , What is the Read command for?