Has anyone ever had trouble with a single channel or multiple channel failure on an AB IB16 dc input card ?

Is it possible to have intermittent failures on a channel

Thanks,
Mark.

 

Why wouldn't it be possible? These are sampled inputs and can miss a short signal. And they don't make them replaceable for no reason. They are pretty robust and reliable, but not perfect. And you can have a "walking wounded" card after an ESD event or many other things that happen in the real world. That's why the first thing after checking the wiring is to swap out the card.

Regards
cww

 

> Has anyone ever had trouble with a single channel or multiple channel
> failure on an AB IB16 dc input card ?

Can't remember if B=Sink and V=Source or vice versa, but in using hundreds of the standard speed positive logic modules (true high) I'm not sure I had a single failure. They're pretty good modules. However, everything can fail.

> Is it possible to have intermittent failures on a channel

Intermittent faults in PCB systems can come from a broken trace. If the board is oriented and force applied to it in such a way that the ends of the trace are pressed together, it works. Changing mechanical loading or component-generated or ambient heat move them apart and No workie! Bring them back together and they're fine.

 

I can't recall if it happened to that particular card or not, but I have had inputs that will not come on, inputs that are stuck on, and inputs that are intermittent.

I once had a Modicon input module that one point would get a spurious on signal now and then. I traced it down by disconnecting the input and putting a counter in the logic to count how many times the input came on with nothing connected to it. Over night with no wire there, it came on half a dozen times according to the counter. The next day Modicon tech support advised that a short run of the modules had this exact problem due to a defective capacitor. A quick check of the card's serial number showed it was in the range of cards that had this potential problem. A replacement card solved the problem.

--
Bob