USB6341 Digital/Counter output voltage

[cls_user]

I hope to use USB6341 to generate a trigger another device that requires 3.3v input. 

I wonder if USB6341 output can be configured to generate 3.3v digital/counter output?

Thanks.

[Wild_man]

The DO pins are not designed to be voltage regulated and therefore do not have a way to accurately provide 3.3V through software configuration. If you want 3.3V from the DO pins you'll need to draw some current from them in order to produce a voltage drop from the approximately 5V they natively output. Their voltage vs. current graphs are shown on pages 8 and 9 of the manual here.

You could solve for what size pulldown resistor would draw an appropriate current to get you to 3.3V, or you could use a potentiometer and a DMM to determine the proper value.

[ben64]

You can use one of the analog outputs of the 6341 to generate a 3.3V pulse.

Ben64

[tonygo0102]

Hi Alex

I have the same confusion regarding the digital/counter output of USB 6341, from its spec description, the output high current is -16mA (-24mA） and output low is 16mA （24mA), does it mean the output signal is current insdead of TTL voltage? And in the reply, you are saying they natively output 5V, could you please explain why it output 5V when the spec only output current information? 

What I am trying to do is using USB 6341 to generate a pulse train signal for a stepper motor driver which requires the input signal at least 5V DC.

Best regards

Tony

[Kevin_Price]

Answer is much the same as this one in your related post.

The 6341 will give you *much* better options than the 6211 though.

- only 1 counter is needed for finite pulse trains rather than 2

- 4 counters are available rather than 2

- buffered counter output is supported so you can define a motion trajectory with smooth acceleration to a high speed while still precisely controlling the total # steps.

The main sticking point with the trajectory is that it isn't trivial to interrupt it part way along and reliably decelerate back down from high speed.   Sudden stops from high speed tend to make a stepper coast a little beyond their nominal expected position.   It's possible the "closed-loop stepper drive" you mentioned in the linked thread will help prevent that, but I wouldn't count on it.

-Kevin P