1794 ia16/a

Hello,

I am currently migrating away from a SLC 5/5 processor to a L33ER Compactlogix. All I/O was on Devicenet (12 nodes) flex I/O configurations.

Testing all remapped and translated (from tool) I/O on node 1 went well. Node 1 is in the same cabinet as SLC. Inputs worked correctly, outputs toggled, analogs changed etc.

My first literal "remote" panel, Node 2, analogs are good, Discrete outs worked. But my digital inputs are intermittently changing. I isolated my move instruction and it isn't that. Monitoring the SP500_AENT:I.Data[0].0 physical input values will reflect accurately, briefly then go to another value from controller tag list view.

Locally at the module the input light indicators are not fluctuating. So it is something between the module and the PLC. I though maybe a dup IP? but then I changed it and the issue persists.

I will be trying another node tomorrow and wanted to ask you experts out there for any tips should I run into this same issue with the next node.
My I/O moves are exactly the same as my successfully working RIO at node 1.

What are your MOV instructions doing?

1794 ia

Just moving the indexed inputs. SP_501_AENT:0:1 to N21[0]. I have another rung with the exact same instruction except SP_500 (different DNET node) and that one functions correctly.

Just trying to determine if it is something possibly on the backplane of the RIO chassis?

Thanks!

bigLee said:

Just moving the indexed inputs. SP_501_AENT:0:1 to N21[0]. I have another rung with the exact same instruction except SP_500 (different DNET node) and that one functions correctly.

Just trying to determine if it is something possibly on the backplane of the RIO chassis?

Thanks!

Click to expand...

Do a cross-reference on N21, and check to see that only that MOV is writing to it. It makes it easy to double-click the header of the "Destructive" column a couple of time to get the "Y" indications at the top. There should only be one instruction flagged as "destructive" ...