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My digital input will not change state.

Hi, i have the USB-6009 and i am trying to read in through a digital line with DAQ Assistant. When i test the port it doesn't change state when i enter different voltage levels, the same is true when used in a LabVIEW program. Any help would be appreciated.
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What on MAX??

Does your Digital channel stay always on a logic high irrespective of what ttl level you feed to that line??

I do not recall very well now, but do check its manual if it needs a pulldown resistor to bring it to Low before using the digital line as an input.

hope this helps

regards

Dev

 

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Hi all,
 
Well Dev is right.
You simply need a pull down resistor for wach of the digital inputs.  If you do not do thins, you can set the digital input high, but you will never be able to set the value low again.
 
I hope this helps
 
AdamB
Applications Engineering Team Leader | National Instruments | UK & Ireland
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