Compact Logix 5370 Output Flickering

[Nick_D 0]

I have a machine that we added an input to. During the addition of the new input, our maintenance team shorted out an output on the main controller. I thought it wasn't a huge deal as we have another output card with spare outputs. I wired the output to the other card and in my program I just added a line that said -|Local:1:O.Data.8|-----(Local:3:O.Data.4). I was under the impression that this would energize O:3/4 when O:1/8 would normal energize.

The output is controlling a valve and the valve does work off of O:3/4 when O:1/8 is running, but it flickers sporadically the whole time.

So far I've tried latching the output and taking the load off the output card and nothing has stopped the output from flickering.

Any guidance is appreciated!

[pcmccartney1 141]

Cross reference the Local:3:O.Data.4 to determine if something else is writing to it.  You are looking for destructive references.

[Nick_D 0]

38 minutes ago, pcmccartney1 said:

Cross reference the Local:3:O.Data.4 to determine if something else is writing to it.  You are looking for destructive references.

I forgot to mention that I've also done that. I've went as far as to trying all 5 or so of my spare outputs and each has the same flickering issue though they aren't found anywhere else in the ladder logic.

[pturmel 157]

What models of controller and card are involved?

[BobLfoot 301]

Add the following code

XIC  Local:1:O.Data.8  ONS DebugONS1 CTU DATA_8_Flickers 0 0

XIC  Local:3:O.Data.4  ONS DebugONS1  CTU DATA_4_Flickers 0 0

This will help you determine if the flicker is from the original code , your new output logic or hardware.