generqte a PWM signal with LabVIEW using digitals outputs

yes, it is really helpful for me, but I have still some troubles, because I confess, I am not very confident with LabVIEW, and I think I am bad too.
So, I need a frequence of 50 Hz, I have changed values and it work, but I need a much better accuracy concerning the duty cycle, it means, a step of 0.1%, but I can't chose the correct values :evil: Could you help me again, pls ?
For the moment, nothing works because "Device identifier is invalid" as it's written. But my device is number 1 too. I don't know why it doesn't work but I'll continu to look for solutions.