PXI 2567 (64 Ch Relay Driver) - Zero Voltage

[Anadyr009]

Hi all,

I apologize for the cross-post, but I am in need of an answer. 

I have a PXI-2567 board I will be using to drive some SP2T switches. I will be using the 12V pin from the card to supply the power to the switches. I tested the 12V pin (pin 19) and ch0 (pin 40) with a multimeter and to my surprise it read approximately 9 V. I then tried closing the channel (ch0->com0) through NI-Switch and when I took another reading it said approximately 12V. How can I set the voltage to 0 V instead of 9V when the ch0 is set to open? If possible I would like to make it a default setting on all the pins. I believe it has something to do with the push-pull circuitry of the channels, but I am unsure what to do with this information.

Any help resolving this issue is greatly appreciated. Please let me know if further information is required.

[crossrulz]

Were you measuring the +12V  to CH0 (ie CH0 was connected to your negative probe) or from CH0 to COM0?  If the former, then I would expect 0V at CH0 giving you a measured 12V drop.  When opened, I would expect some leakage to COM0 and you would therefore measure the voltage drop from your load (which appears to be 9V).

[Anadyr009]

Hi Crossrulz,

Thank you for your reply.

I was doing +12V to ch0 pin when it was open, it read 9V which is why I'm so confused. When I closed (ch0->com0) it on NI Switch and measured (+12V to ch0 pin) it read 12V. So from open to closed it goes from 9V to 12V. My leads on multimeter are always at the same place (pin 19 for +12V and pin 40 for ch0).

I tried measuring other pins besides ch0 and they were all the same. If I measured +5V to ch0 when open, it was approximately 2.5V. When +5V and ch0 (ch0->com0) was closed and measured it read 5V.

I tried measuring ch0 (open and closed) to ground on computer chassis and it read 0V as expected. I measured +12V to ground on computer chassis and it read 12V as expected.

[crossrulz]

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Anadyr009 wrote:

I was doing +12V to ch0 pin when it was open, it read 9V which is why I'm so confused.

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So the output is actually at 3V relative to COM.  Did you have anything connected to the output?

[Anadyr009]

Nothing physically connected. I measured the pins directly on the PXI 2567 board.