Quantum Analog Input Card

Hi guys,
I have a problem. A client of mine is using a Quantum ACI04000 analog input card. This is a 16 channel unipolar card.
He is complaining saying that all the channels on the card are reading low all of a sudden.. Normally the values should be in the 0-16000 range but now at 20mA the signals are only 15380.

Does anyone have any ideas on what the cause is?

Your help is appreciated.

I Think this is set up using an external power supply? If so, check and see if supply is measuring 24V. Did he just add another input, or are there more inputs that are running toward the 20mA side? If the current draw is greater then what the power supply puts out, the high end tends to start going down.


George

Thanks for the reply.
I will check with him what the PSU is putting out.
The Analog input card sits on a 16 slot backplane. The PSU powers the backplane aswell as all other devices on it such as CPU, comms modules, other I/O cards.
It could be that he is running alot of devices off the same power supply. However, wouldnt that cause the problem to occur from day one itself? He reckons that this problem has just strated happening.

If this is the issue, are the outputs running closer to 20mA then normal? Can he measure the current draw of the Power Supply, and is it close? Did they even add readouts to some of the inputs? One way to test if this is an issue, can he safely remove a few inputs?

George