[emilylee]

Hi, All,
New to this forum. Do not know if this article goes to the right place.
I bought a new 4 wire bipolar stepper motor and motor driver from one company. The driver needs 5 V pulse to drive. So I am using a Digital I/O interface NI 6501 to generate this pulse as well as a high or low voltage output to control the direction. However, I cannot even drive the motor running. So I checked the input on the driver from the NI 6501. I do have a pulse generated 0-5 v. The direction output is right if not wired with the driver. When wired with the driver, it oscillates with the pulse. So wired. But the output from the driver between A+ and A- or between B+ and B- never changes. It is always 0 V for A phase and 24 V for B phase. Btw, the driver has a 24 V DC input power. Does anyone know what is happending? What can I do to test the driver chip?

Thanks,
Emily

[george4657]

It would help if you told us what driver you have and if possible a link to the driver.
Many drivers have an enable pin that needs to be set to run, have you checked this?

georgeG

[emilylee]

Thanks, George.
This is the link of the driver.
https://www.circuitspecialists.com/s...er-qj-215.html
It does have a ENA pin. But the manual said this pin is 'motor free'.
Do I need a logic high voltage to enable this pin?

It would help if you told us what driver you have and if possible a link to the driver.
Many drivers have an enable pin that needs to be set to run, have you checked this?

georgeG

[emilylee]

Have wired the ENA pin. The stepper motor is not running.

[george4657]

The only reference I could find on the internet was that enable had to be 5 volts. If it is not I would try it tied to 5 volts through a low value resistor (300 - 600 ohms) just to be safe.

[george4657]

When power is supplied is the motor locked in position or very hard to turn. This would indicate that the motor is hooked up correctly.

[emilylee]

I can rotate the motor using my hand before wiring the ENA pin. After wiring, I cannot. The ENA pin should be wired. But still I cannot make the motor running...
Does NI 6501 a good choice here to generate a pulse? I used a oscillascope to monitor the pulse. It is good. I can easily generate a pulse with 50ms width.

[emilylee]

Just checked again. When the power is on, even without the ENA pin wired, I can not turn the motor.