1746-NI4 error

Is it really 0V input? You actually have a signal source hooked up to the input terminals? What does it read if you short the input terminals? Is it configured for voltage or current?

The channel #2 of my 1746-NI4 module reads -3000 with a 0V input. Is there a way to fix this? Channel 1,3 and 4 works fine and read around 0 when 0V is inputted.

Yes, it can be fixed.

Is post #1 a response to post #2? Or am I getting too much sun?

I noticed the backward flow myself. I've also seen it in other fora. I suspect it has to do with server maintenance.

My post is the 2nd post.

Anyway, yes when I jumper the - terminal to the + terminal, I get a -3000 reading. Is there a way to recalibrate the module?

david90 said:

Anyway, yes when I jumper the - terminal to the + terminal, reading. Is there

Click to expand...

When you installed the jumper did you also jumper to the ANL COM ? See picture.

That is a pretty big error to calibrate out, but see manual below for a method to do so. Appendix C

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1746-um005_-en-p.pdf

Mickey said:

When you installed the jumper did you also jumper to the ANL COM ? See picture.

That is a pretty big error to calibrate out, but see manual below for a method to do so. Appendix C

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1746-um005_-en-p.pdf

Click to expand...

No I did not. However, I did the same thing to the other 3 channels and they read around 0. Thus I think something is wrong with channel #2's hardware. I'll try to jumper to the ANL COM terminal also and will let u know the result.

I rather not use the module if I know something is wrong with the hardware.

david90 said:

I rather not use the module if I know something is wrong with the hardware.

Click to expand...

There's no harm in using the module just because 1 channel has failed. I would document the bad channel as unusable if I did install the module. Most I/O systems carry a few bad points, as they fail during production and get reassigned to spare points to avoid the downtime required to exchange the damaged module.

So long as the failed point isn't affecting the other channels, nor the backplane power, there will be no problem.

Its a SLC. If you have a spare card, you card swap it out without tools, since the analog modules use phoenix style pin connectors.

It has been my experience that one failed channel may indicate near end of life of other channels, and it is better to R&R (remove and replace) when a power outage of the rack is feasible.

Then you don't have a paper circle chase afterwards as a bonus. I have had cards with channels that "come and go". I mark them "X" with a fine red sharpie by the serial number and stick them in the test pile for shop tinkering. You don't want to pay the shop for "no problem found" over and over again, and weird SLC cards are aplenty.

So, yes, move the channel if it's easy and okay with the company, but get a spare card lined up, and do disconnect the wiring from the known bad channel.