How to read the state of a digital output?

[patufet_99]

Hello,

When using standard multifunction NI-DAQ cards (as the M series), is there a way to know the status of a digital output?

When executing a VI, at initialisation I would need to know the actual status of the digital outputs without having to changing it.

Thanks for your help.

[martin@aerodynamics]

Hello,

When using standard multifunction NI-DAQ cards (as the M series), is there a way to know the status of a digital output?

When executing a VI, at initialisation I would need to know the actual status of the digital outputs without having to changing it.

Thanks for your help.

Hello it's quite easy, have a look at following example:

So just use DAQmx Read to read an Digital Output.

But be careful if you invert a DO Task, and you read the DO Task with DAQmx Read, the result is not inverted!!

I don't now if this is a bug or if this has to be. In my opinion it's probably a bug...

Because if I configure a Task as Inverted, I expect also the read to be inverted (if I use the Task Name and don't read direct a DO over it's DO number (port etc.)

[patufet_99]

Hello Martin,

Thanks for your reply. As you noted is quite easy! I was just disturbed by the fact that digital ports can be used as inputs as well as outputs.

Merry Christmas and thanks again.

Regards.

Patufet

Hello it's quite easy, have a look at following example:

So just use DAQmx Read to read an Digital Output.

But be careful if you invert a DO Task, and you read the DO Task with DAQmx Read, the result is not inverted!!

I don't now if this is a bug or if this has to be. In my opinion it's probably a bug...

Because if I configure a Task as Inverted, I expect also the read to be inverted (if I use the Task Name and don't read direct a DO over it's DO number (port etc.)