Writing to DAQmx Channel does not update phisical channel on DO card

Hello guys,

I have created a program to control a valve with PWM signal.

Here I create and run the task:

And here I change the pulse width:

I can see, that the Pulse Width property does update, but on the channel does not.

I also tried this, but its the same:

What am I doing wrong?

HW info: cDAQ 9172, NI-9474.

NI-9474 card is mounted on cDAQ slot 6.

Best Regards,

Jakob