push button on digital port

[Exovede]

Hi,

    I'm trying to use a simple push button on a digital port line on a 6225 card without using an external pull-up (really, a simple on-off switch).  I can plug the switch with a coax on an interface connected to the digital port.  For now, I would only poll this port.  What I want to do is that if the button is open, the voltage read from the port should be 5 volts and when the button is close, zero volt.  I tried setting the starting state to 1 (TTL high, 5 volts) for this port but this doesn't seem to work.  Maybe I'm missing something and being thick but I have no luck for now.  Thanks for any advice you should have.

[Edit] Programming on Labview 2009

Salutations,

Michel

[Carisa_L]

Hi Michel,

Are you trying to write to or read from a digital port line? I would really appreciate it if you could clarify what your goal is. In the meantime there are some great examples that you can find here: LabVIEW>Help>Find Examples...     Hardware Input and Output>DAQmx

Cheers,

Carisa

[Exovede]

Hi Carisa,

    Just plugging an on-off switch to the digital line (DIO0 - DGND) without an external pull-up.  If the switch is open (normally this would be the case),  I should read 5 volts from the DIO0 line.  If the switch is close, I should read 0 volt.   As previously stated, the card is a PCI-6225 (but I could also use a PCI-6229).  Is that possible or I really need an external pull-up?

Thanks again,

Michel

[Carisa_L]

Hi Michel,

In this case, I believe you would need an external pull-up resistor. Hope this helps!

-Carisa