Analog input Stops reading in 2 channels randomly

[Vprakatoor]

Hi

 

I have a Unistream with the following modules and positions

UID-1600 @ 0    Di module

UID-0016R @ 1 DO relay module

UID-0402N @ 2 AI/AO module

UID-0402N @ 3 AI/AO module

 

I dont have any analog outputs on the UID-0402N modules, on one of the 0402N the 4-20ma signal coming in on channel 4 from a level transmitter randomly reads 0% for 2 mins and then comes back  to actual level after that for 2 more minutes and then goes back to 0 for 2 mins and so on. while this is happening the display on the transmitter reads correct the whole time and the 4-20ma on the terminal blocks read fine(checked with meter). If i power cycle the UNIStream the problem gets fixed for a few days and then it starts up again. any help on this would be greatly appretiated.

 

[Flex727]

The first thing I would do is swap the two 402 modules and see if the problem moves.

[Vprakatoor]

1 minute ago, Flex727 said:

The first thing I would do is swap the two 402 modules and see if the problem moves.

Hi Thanks for your reply,

 

If i swap the modules and the wiring terminals, do i have to make any changes to the hardware configuration in unilogic?

[Flex727]

No.

[Vprakatoor]

1 minute ago, Flex727 said:

No.

Thank you, I will try this today but the problem is the event is random and happens every week, I dont have any way to force/simulate this issue so i wont know if it solved my problem for a week or so.

[Flex727]

45 minutes ago, Vprakatoor said:

so i wont know if it solved

The suggestion wasn't to solve your problem - it was to help isolate the location of the problem.

[Ausman]

In addition to what Flex has said, have you monitored things online when the issue is happening?  To ensure that the raw reading is changing, rather than something in your program doing this.

cheers, Aus