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USB 6008 digital output

Hello, I'm new to labVIEW and using DAQ cards. I've been trying to run the "test panels" program to successfully get my card to output a 5V signal on any of the lines in port 0 or 1. When I set port 0 to output and select "all high" I would expect a multimeter to give me 5V when I measure any line, from 0-7, compared to the ground but this is not the case. I've just been getting <20 mV noise. I also tried to run the "self-test" which just says it completes successfully with no extra information. What else should I be doing to get a 5V output? Is there something I'm missing?

 

I am eventually going to use the card to operate 11 valves with each line turning an individual valve on or off.

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Do you have the lines connected to anything or are you just probing the screw terminals? The test panel should work if you don't have anything connected.

The self test really only verifies communication.
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I have nothing connected right now and am just probing the screw terminals.

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rtjoyce wrote:

I am eventually going to use the card to operate 11 valves with each line turning an individual valve on or off.


You will likely need a buffer circuit since the 6008 cannot supply much current at all.  If you are already connected to these, then that is what your issue is (current limit for the output only allows the output voltage to be really small).


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What ground are you measuring to?  Make sure it is the ground on the 6008.


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I have additional circuitry to allow the minimal current to operate the valves. I am currently just having a problem reading out a voltage from the card.

 

I am also measuring relative to the ground on the digital side of the card

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Are you probing from the top of the screw heads or do you have wires in the slots with the screws tightened down on them?

 

The reason I ask is that on some terminal blocks, if the screws are fully loosened, they no longer make contact with the lower contact that completes the connection.

 

I have encountered this once and learned a lesson.

 

-AK2DM

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Did you ever figure this out? I am having a similar issue but with a PXIe-6361. 

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Yes, I thought marked solutions were more apparent. When I changed the leads and used the 5V terminal as the high, it turns out that it has significantly higher available current than the others. So I use the other lines to act as a low to turn the valves on and high to turn them off and the potential difference between the 5V terminal and individual line gives me what I need. Hope that helps.

 

Oh weird, for some reason the previous post that had the answer in it disappeared. If you need a better explanation of what I did to solve it let me know.

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