Logix Drive device status incorrectly reported

Ignition
1

Pretty niche issue but we have a Control Logix setup with two L73 PLCs sharing a common EN2T. We’ve noticed in the course of testing that if a PLC is physically removed from the rack the device status reported by ignition still reports connected. The Console is spamed with connection failure errors from the LogixBrowseStateManager (see attached logs for exact messages). OPC browser is still able to “browse” to the PLC however there is nothing under the PLC name in browser (no programs or tags). It seems the status being reported back is only the status of the ethernet connection not the entire CIP connection.

Shouldn’t the status report a timeout or error of some sorts?

Not really a major issue since typically PLC arn’t removed from racks (we only noticed by chance when packing up the PLC for shipping). However I would assume backplane and Processor issues would also show this incorrectly.

Server:
Windows Server 2012 R2
Java 1.8.0_25
Ignition Platform 7.7.1
Logix Drive 1.7.5-rc2
OPC-UA 2.7.1

PLC:
slot 0 - 1756-L73 Version 26
slot 1 - 1756-L73 Version 26
slot 2 - 1756-EN2T
slot 3 - Blank

2

Hmm. This is a weird corner case that we should probably try to figure out a better way to handle.

What’s happening is that you actually are connected, because the connection is made to the EN2T, and even after removing the processor you were routing to the connection remains open and valid. After removing the CPU you start get errors because the target of the connection is no longer valid, and of course an explicit connection can’t be opened and a browse can’t be completed…

At that point you’re basically in the same situation as if you had misconfigured the slot number when setting up the device.