dig_in_line high on startup PCI6503

[Hawk 266]

I need to use NI-DAQ to read a single digital line, on a PCI-6503 card, to detect the state of the input. But when I start my application (developed in VB) it is showing a high state. It only works when in Max 2.1 I send an output to one of the lines. Is there some initialisation I'm missing out on?

[Filipe A.]

Hawk;

It's not that clear to me how exactly you are testing the digital line. Do you have anything connected to that line? Are you actualy trying to read a real digital state? Otherwise, if you don't have anything connected you might read only high states.
To check if the Software was written properly, you can test one of the example codes that ships with NI-DAQ.
If you go to C:\Program Files\National Instruments\NI-DAQ\example\VBasic\DI\DIOneLine.
Hope this helps.
Filipe

[hk 278]

Hi, I got same problem too.
when I run "VBasic\DI\DIOnePort" example, it shows "255".
When I change the default state into "pull-down" by setting the jumper, the "DIOnePort" example shows "0"
I got same result even though I have connected one pin(say pin47, pa0) by +5V battery.
Thus I still can't read a real digital state .

Pls give your expert advice on that how can we read a digital input state. What is hardware configuration?

Thx.