View Full Version : No Pulse?


jubee
07-06-2004, 06:44 PM
Can anyone tell me if there is a way of checking the step & direction pulses from the printer port ,(either with software or hardware) as I have a problem
running these 3, dc servo motors and as Iam not sure whether
its the 320 gecko drivers or the computer.
All 3, 600oz/in ametek motors remain in a locked position with power applied and with no movement during running some gcode or trying to jog the axis using turbocnc,mach2and kcam.As soon as the wires are taken of the encoder the motor stats to spin.Bit like my head is starting to.
Anyone with any ideas or suggestions!

High Seas
07-06-2004, 06:56 PM
I was going to get a breakout bard- a small unit that looks like a "gender changer" with with LEDs s to error check signals - instead I just just swapped computers and the problem I had was too low voltage on the laptop!
Are you on a laptop - some only drive at 3.3 volts and if you need 5 - well, there you go,
Cheers - Jim

jubee
07-06-2004, 10:27 PM
Thanks High Seas,but I have tried two different computers,both
desk top pentiums, one a p1 and the other p2 400mhz,and still no go.
On checking the volts at the step and direction terminals of the 320 geckos indicates 5v?

Cold Fusion
07-06-2004, 10:55 PM
Jubee, I'm in the same boat as you, the "I can't get this crazy system to work" one. You might want to try in Mach 1/2 switching the port options to hi active.

jubee
07-06-2004, 11:35 PM
I think I have tried every possible combination,(HIGH low config) software that is and still no movement,Thanks anyway .

Whats interesting is without the computers parellel port connected to the interface card ,both step and direction terminals
on the geckos show 5 volts(+- 0.02). On connecting the computer up, the volts drop to 4.8v? I dont Know if this is normal.

Thinking it may be a low volts problem I have just checked my
P4 computer printer port and it indicates 3.8v????go figure.

HuFlungDung
07-07-2004, 12:00 AM
Make sure that you remember to command a feedrate when trying to run Gcode. This is a common oversight for the newbie. The first G01 must have a feedrate.

jubee
07-07-2004, 03:09 AM
Thanks HuFlungDung, but still no good.
Its looking really good as a boat anchor at the moment.

I just tried hooking it up to my main P4 computer and not a movement ,still the motors stay in the locked position.

Any Idea what voltage the step and direction terminals on the 320 geckos should read,with and without the computer connected?

HuFlungDung
07-07-2004, 09:50 AM
Jubee,

Mariss at gecko should be able to help you out with all the info you would need on the gecko drives. Have you contacted him for troubleshooting procedures?

HomeCNC
07-07-2004, 04:48 PM
It would seem that you have tried more than enough computers to rule out the LPT port. Unless you somehow have the wrong LPT port called out in the software. Some can use two ports.
Oh and just to cover it. Make sure the LPT port is turned ON in the PC's CMOS setup.

That leaves two other things to check. The wiring and the config of the step and direction software.

Let's just look at one G320 drive and call it the X axis drive.

Look at the picture below and re-check your wiring. Where are you getting the +5 VDC power for the Gecko drive? (I use an external wall wart).

To charge the G320 just jumper the "Err/Res" to the "Enc +" and hold this for a few seconds. To dis-engage the G320, jumper the "Err/Res" to the "Enc -"

Double check your software that pin 2 and 3 are set correctly. If you are using Mach 1/2 you will need to define Jog keys.

Mariss Freimanis
07-08-2004, 12:27 AM
It's easy to check a port for step pulses. Find one of those little irritating PC speakers you can find in every PC case. Connect one lead to PC ground, the other to the port output pin you think is a STEP output. If it is, the speaker will reward you with a very nice squeal. You'll even hear the acceleration, run and deceleration frequencies.

Mariss

jubee
07-08-2004, 05:11 AM
Thanks guys for all your help,but I think I found the problem,
A dodgy brand new printer cable.

I placed a couple of wires into the back of the pc`s printer port
then straight to the geckos, and presto!!!!!!!!!

Motion at last .

Sorry Mariss I didnt get to try your speaker idea
out but will keep it for next time.
By the way my emails must not have got to you.