How can I read what I wrote to a DAQmx digital output channel

[DillonL]

Hi!  These older threads are great for reference, but you might have better luck getting help from the community if you created a new thread since this one has some age on it.  Have a good day!

[blima]

I will contribute to this topic because it was useful to me. I am trying to develop a driver for one of the NI devices and faced the need for reading the current digital output state.

We discovered that the commands to read the states of the digital output port through a task do not lead to an exchange of USB packets in communication. The exchange of packets happens only after a write command.

In fact, the task retrieves the state of a task channel, which is a virtual channel. In summary, it is a representation of the physical channel contained inside the library, not actually the physical channel.

The way we read from actual physical channels from the Python API is through the DigitalMultiChannelReader, which is able to read only from inputs - not outputs.