Control Logix5000 MSG Function Over Ethernet

[Liambee11 0]

I'm having a bit of difficulty with the MSG function on a logix5000. I'm simply trying to get a REAL value ("BH5_Flow") out of another logix5000 and assign it to a tag in the PLC. I've created a MSG function and created a new tag "BH_5_Flow_MSG" for the message, and created "BH5_Flow_M" for the value that will come from the MSG function. When I click the "..." button to bring up the config, I put the following in: Message Type: CIP Data Table ReadSource Element: BH5_FLOWNumber Of Elements: 1Destination Element: BH5_FLOW_MIn the PATH tab, i then put the following in: Path: LocalENB, 2, [iP ADDRESS OF SOURCE MACHINE]When I test the edits, I then get the ERR bit activate with error 16#0004 when the message rung runs. Anyone got any ideas where Im going wrong? I've practically copied another MSG instruction from further up the ladder but it doesn't seem to work

[Ken Roach 194]

Unless the source machine is a new model CompactLogix 5370 series, you also need to specify the Backplane Port and Slot Number of the target ControlLogix. If the target ControlLogix is in Slot 0, you just need to add ", 1, 0 " to the CIP Path. Obviously change the Slot number if the ControlLogix is in a different slot. That also works if it's an older CompactLogix or FlexLogix controller; they were always considered to be in Slot 0 of a virtual backplane object.

[ASForrest 12]

If these are both logix 5000 controllers, you can also use produced/consumed tags for the data transfer, which is a much neater and simpler solution. Have a read up on them and see if they will suit your application. If you are sticking with the MSG instructions for consistency or backward compatibility or some other reason, then, what Ken said :)

[Liambee11 0]

Thanks alot for this! I was quite suprised that the "Browse" feature for identifying the Path could not follow the Ethernet module any further, at least I couldn't get it to anyway. I expected to click on the Ethernet module and for it to expand and show everything on that network, similar to how Linx can manage networks. Perhaps AB will expand on this in the future

[Ken Roach 194]

As I understand it, the CIP Path browse feature isn't interacting with the network, but only the I/O tree objects inside the RSLogix 5000 file. If you have a remote PLC with a connection for Produced/Consumed Tags, then it will show up, but otherwise you need to plan the CIP path manually. There's a hack for using RSLinx Classic browsing and OPC topic definitions to determine really complex CIP paths, but in this case just stick with manually entering the last two hops.

[MrAutomation 20]

You haven't added the processor of the other device to the io tree, which is why you can't browse to it. Adding the slot number manually works fine though.