PXI-6509: How to select if a disconnected Digital Input should be seen as 0 or 1 ?

[snicolay]

Hello,

I am using the PXI-6509 to acquire the digital states of a bench that has the following behavior:

0 = pin connected to ground

1 = pin not connected

I can not modifiy the bench, and my 6509 always see 0 => Is there a way to tell it that a non connected pin should be see as 1 (i.e. internal +5V) ??

I have las version of MAX and LabView 8.0.

Thank you very much

[Buechsenschuetz]

I am not familiar with this board. But usually digital inputs are tied to +5V via a pull-up resistor so that the board will see a logic high level if the input is disconnected, so this behaviour looks a bit strange to me. Anyhow, in case there is NO pull-up resistor onboard you can fit your own. A resistor with a value between 4.7kOhms and 22kOhms tied from the input to +5V will produce a logic high level on the input line.

[snicolay]

Thank you Buechsenschuetz,

but in fact, I can not modify nor add any hardware. There is a special cable that go out from the 6509 and that is connected to the bench, and I don't have access to this cable and I don't have access to the bench that is part of a satellite. The only thing I can do is configuring the 6509 in the good way, or using another board but which one ?.

I don't find anywhere how to configure it and if it is possible to.

Besides, I also thought there was a pullup inside, and I don't understand this behavior too.

Thanks to anyone who could help me.