Hi Poline,
That's some really unusual behavior that you're noting. You mentioned that the board was repaired in Sept 2005. Why was it repaired? Was it working when you got it back? Has anybody else been using the board? Do you have any other boards of the same type so that you could do comparison testing?
You're definitely right that the calibration procedure won't really fix anything. If your measurements were about 1mV off and you wanted to correct the offset, then you might want to calibrate the device, but getting a voltage of 1/2 of what you specify is very different.
I'm always really suspicious of problems that involve integer values. Typically that means there's something wrong in the software or a voltage divider is being used unknowingly.
There's really 2 sides of this that we could test, Hardware and Software:
Software:
Try installing the drivers on a fresh computer and then insert the board in question into there. Open up MAX and see if the characteristics are the same in this other computer as they were in the first. If so, then it means the problem is Hardware related. If the problem vanishes, then it means that something is going on in software and we would need to know more about your SW to figure out what exactly is happening.
Hardware:
There are 2 things that could be going wrong here - Faulty Measurements or Bad Output
Faulty Measurements - Since you can't read the measurements with your AO board it means that you are using a different device such as a multimeter. Try measuring a known voltage such as that from a 9V battery. If you read 9V, then it probably means that your measurement device is working.
Bad Output - Try creating a simple program and output various voltages including such things as a sine wave and see if there are any other bad characteristics in the waveform. If so, then there is a possibility that something is the matter and the device should be sent in for repair. If that's what you want, then contact an NI Support Engineer (ni.com/support) and they can help you verify that it's not working properly and coordinate the repair.
Just remember that if you send the device in for repair and it turns out to be functioning, just some detail was looked over during testing that you will be without the product while it's being tested, have to pay for shipping and the repair of the functioning device. That's reason enough to make sure that you try all possible steps first before sending it in.
If it really is broken though, we'd be happy to repair it and will get you back up and running as soon as we can.
Hope this helps,
