why is the pci-6221 analog output value -10 V when computer is powered on?

[LarryL]

Hi, All,

I try to use pci-6221 analog output to control a actuator. The analog output from pci-6221 is - 10 V when computer is powered on and that causes the actuator out-of-control. Why is the pci-6221 analog output value -10 V instead of 0 V when it is powered on? Is there anyway to set it to 0 V?

Thanks,

Larry

[jschwartz]

Hi Larry,

This shouldn't be the case when you power on your 6221.  I have the same card in my computer and when I read an analog output channel that I am not running a task on, I read right around zero volts.  M series cards do offer programmable power up states for the digital lines, but this is not available for the analog output lines.  Is the card working as expected other than the startup or does anything else seem to be messed up? I would try powering down your computer, switching PCI slots, then powering up your computer again to see if this alleviates the problem.  

[LarryL]

Hi, Jim,

Thanks for the response.

I actually switched to different computers and problem was the same. It only happened at startup and everything else seems fine. It would be a issue for the end user/operator. That's why I try to solve this problem before we ship it to the end user.

I am wondering if it possible to program analog output power up status as digital IO lines. Why can't  it be done?

Thank,

Larry 

[Dennis_Knutson]

If you want the ability to set the power up state of tha analog output, you can go to the Product Suggestion Center.

However, I can confirm that the default power up state is 0V just like Jim said. Are you measuring the voltage with it connected to some sort of load? If so, I would suggest disconnecting it and repeating your measurement. If you still still a -10V output, it's possible the card has gotten damaged.

[jschwartz]

Hi Larry,

If you suspect that your card is damaged, you can create a service request at ni.com/ask.   Make sure to set the Question Type to Returning hardware for repair/raplacement/calibration.  You can then call 1-666-275-6964 with the service request number.