[Digital Output Problem] PCI-DIO-96

[insomnia]

I am using a NI I/0 card (PCI-DIO-96) with DAQmx libraries under Linux.

I compiled and run the example WriteDigChan.c.

After i run this example, i used a multimeter to measure the voltage at each line and check if the card is working properly.

The problem is that when a line is set to logic low (0) the voltage i measure is ~4,916 Volts and when a line is set logic high (1) the voltage i measure is 0 Volts.

Shouldn't be viseversa? Or am I missing something?

[scmave]

Hi Insomnia,

This card is probably active low output by default - meaning that a low (0) will result in an active voltage. In this case since your Vcc seems to be 5V, a 0 output will result in roughly 5V being output. This also means that a logical 1 will be ouput as around 0V.

You can invert the lines using the DAQmx property function call DAQmxSetDOInvertLines.

[K C]

Hi,

I used this board years ago and the outputs are not inverted or active low.

The output should be as expected a '0' is 0V and a '1' is 5V.

Are you not measuring between a output and the +5V ??

Kees