Two ControlLogix chassis, both 1756 L73. Chassis A has a 1756-EN2T in slot 1, chassis B has an EN2T in slot 1 at 192.168.10.12 and the controller in slot 3. I'm adding a CIP Data Table Read from A to B, one DINT array.
The MSG errors straight away, .ER set with 16#0005, and the Communication tab says Path destination unknown. Chassis B pings fine and RSWho sees it with the controller in slot 3. The path I typed is 1,1,2,192.168.10.12,1,0. I retyped it and swapped the target tag for a single DINT, same 0005 both times.
In TIA I'd point a PUT at the partner's IP and rack/slot and it just goes, so I assume I've got a rack/slot thing wrong here too. Is 0005 telling me the path is wrong, or that chassis B won't take the read at all, I'm not sure which end to blame.
Doesn't have to be anything. Last two numbers of your path, read them again.
OG
> Last two numbers of your path
1,0. Backplane, slot 0. But the controller in B is in slot 3, I said that myself. So 1,3, I think. Is that really all 0005 means, wrong slot?
That's all it means. The path is a list of hops: 1,1 is A's backplane to slot 1, the EN2T. 2,192.168.10.12 is out that module's Ethernet port to B's EN2T. Then 1,3 is B's backplane to slot 3, the controller. You sent it to slot 0, which in B is an I/O card or an empty slot, and a CIP read to something that isn't a controller comes back as 0005 path destination unknown. Same idea as rack/slot in the PUT, just written hop by hop. Don't type paths. On the MSG Communication tab hit Browse, walk to B's controller in the tree, it writes the path for you. Writeup on path syntax and the other 16#00xx codes: https://plctr.com/utilizing-ethernet-ip-in-plc-communication/
Browse wrote 1,1,2,192.168.10.12,1,3 and the MSG went .DN first scan. 50 DINTs, 20ms or so round trip on a timed trigger.
So my typed path ended at slot 0 and the controller is in slot 3. Browse on the Communication tab from now on.
One thing I still don't have straight is why the 1,0 didn't error with something more specific, there is a 1756-IB16 in slot 0 of B. Maybe 0005 is just what a module replies to a read it doesn't understand.
Thanks billr, rsdave.
Typed paths are how half of these threads start.
OG