NI 9401 edges counting forward/backward

[terrycong]

How to pragram this application: Pulses will be generated when motor moves, 9401 can count this pulse train when plugging in slot 5 or 6 of 9172. How can i accomplish this: when motor moves clockwise, the pulses count is 1,2.....100; when you chage motor direction, let it move anticlockwise, pulses count will be 100,99.....1. BTW, the motor is brushless DC motor with hall sensor.

[KyleBryson]

Hi terrycong,

You can use an external signal to control whether a counter counts up and down.  The NI-DAQmx Express VI Tutorial shows how to set the count direction to an external source.

If you're using a quadrature encoder, there's some how-to information for configuring those, and the example even uses your exact hardware!

Regards,
Kyle

[terrycong]

thank you for your reply, I have solved the problem successfully.