Can PCI-6520 be used to determine change in resistance?

[LostInTransit]

Does anyone know if the PCI-6520 can be used to determine a change in resistance? 

I have a simple switch that will be connected to the inputs and I'd like to be able to determine if the switch is open or closed. 
If anyone knows how I would program this (which NI functions) using NI's c++ API that would be great too!

Thanks.

[Nick_F1]

Hi LostInTransit,

Thank you for posting on the National Instruments forums.

The PCI-6520 only has digital input and output so you would not be able to directly detect whether the relay is open by checking it's resistance. 

Are you using an external relay, or the relay that is on the board?  If you are using the relays on the board, then you will be able to control it, so you will always know what state the relay is in.

[LostInTransit]

Thanks for the reply but alas, I am still unsure of what to do.

I have the PCI-6520 connected to the CB-37FH screw terminals.  I wanted to connect a simple button switch (that locks on or off) to the screw terminals and be able to determine the state of the button (open or closed circuit).

What kind of setup do I require to be able to determine if the button has been pressed (and locked down)? 

I gather I would be using the relays on the board.  If I can monitor the on-board relays, how can I use this button to change the state of the relay?

Thanks again.

[LostInTransit]

Is it possible to connect my push button switch to one of the Normally Open relays and monitor it to determine if the relay circuit is closed due to somebody pressing the push button?

thanks again for your help.

[Dennis_Knutson]

Sensing an open or closed relay is really basic. Use the circuit below with a digital input.

Message Edited by Dennis Knutson on 08-10-2007 07:45 AM