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Author Topic: High output 2.4V, Low output 2.0V.....this is abnormal?  (Read 2481 times)

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High output 2.4V, Low output 2.0V.....this is abnormal?
« on: February 26, 2010, 05:59:17 AM »
Hi.
This is my first time posting..Have done several post on www.cnczone.com.
Spent hours reading on this forums, but unable to find my answers.

Question:  According to every where, I should be getting 0 = Low  or close to 5V= high for output to run.
Yet...I do not get above 4V in either LOW active off/on?   In fact, I only get about 2.5V out to my terminal DRIVE input...
Any problem this will cause? 

Here is the tested data:

*****Direct connection PC to Driver--no breakout board**** (and yes...motor moving in both direction!!)
Low Active = OFF (dir and step)
Dir = 0.09V in one direction, 2.0V in another direction
Step = 0.00 V in off state, 0.16V in Jog running state

Low Active = ON (dir and step)
Dir = 0.09V in one direction, 2.0V in another direction.
Step = 2.98 V in off state, 2.83V in JOg running State.


Jeff

Offline Hood

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Re: High output 2.4V, Low output 2.0V.....this is abnormal?
« Reply #1 on: February 26, 2010, 06:10:01 AM »
You have a 3v port by the sounds of it, the voltages you are seeing are normal for that. You will likely run into problems and may be better getting a breakout board that can happily work with a 3V PP and will output 5v to your drives.
The reason the step shows mV when active high is because it is a pulse and your meter will just be getting the average over time, the faster you pulse the higher the average will be, so dont be concerned about that.

Hood
Re: High output 2.4V, Low output 2.0V.....this is abnormal?
« Reply #2 on: February 26, 2010, 07:00:14 AM »
Thank you Hood.
I have seen your experted comments on many post.  I am not awared as there is such a 3V parallel port. 
Will change it to different PCI port...perhaps I can use this port for input only?
Re: High output 2.4V, Low output 2.0V.....this is abnormal?
« Reply #3 on: February 28, 2010, 09:18:15 AM »
Just an update..
I brought new PCI breakout board....setting the 2nd parallel port and it work fine!!

But what actually happen was:
My breakout to stepper Drive was wiring in a way that I need to connect +5V to PUL+ and DIR+......but I wire Ground Pin to those terminal instead..
So with that said...I rewired and kabooom....I get +4.5V in one direction, 0V in another direction as it should be......
But for STEP pulse...I still get about +0.4V when click JOGGING...
is this sound right?

Offline Hood

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Re: High output 2.4V, Low output 2.0V.....this is abnormal?
« Reply #4 on: February 28, 2010, 09:26:01 AM »
Yes the step  is  a pulse so your voltmeter will not be able to refresh that fast so it will just see the average voltage, if you hooked up a scope you would see a square wave that goes between 0v and 5v at the frequency you are jogging at.
Hood
Re: High output 2.4V, Low output 2.0V.....this is abnormal?
« Reply #5 on: March 02, 2010, 01:00:28 AM »
Yeah..what was I thinking..
Thank you for pointing that out.