5069-IF8 channel showing 3mA with nothing on it

phuz · Jul 25, 2022

Got a trouble call this AM from a customer saying they lost a level input. Looking at the input, I could see the signal was < 4mA, but not 0. Rescaling the channel engineering units to 4-20, I could see the input was a solid 3mA. They tried to feed 4-20 into the card, but no change. Moved to an open channel and all is well. What causes a channel to go into a state like that?

arpus4KM · Jul 25, 2022

if it was faulted/broken and the configuration is set to default to specific input level, that would be my guess. It all depends on how it is set up.

you can see something about it here on page 49

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/5069-um005_-en-p.pdf

If you're just talked about why a card would just fail, then any kind of surge can kill a loop input. I've had to switch over a few of them at pump stations that had been hit by lightning over a weekend. It fried wiring and fried the inputs.

phuz · Jul 25, 2022

IanM8040 said:
if it was faulted/broken and the configuration is set to default to specific input level, that would be my guess. It all depends on how it is set up.

you can see something about it here on page 49

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/5069-um005_-en-p.pdf

If you're just talked about why a card would just fail, then any kind of surge can kill a loop input. I've had to switch over a few of them at pump stations that had been hit by lightning over a weekend. It fried wiring and fried the inputs.

Thanks, that's what I was looking for. Not sure what killed the channel, but it's dead. Didn't realize they clamped it at 3mA.

5069-IF8 channel showing 3mA with nothing on it

phuz

Member

arpus4KM

Lifetime Supporting Member

phuz

Member

Similar Topics