Motors never reverse

Hello,

I have just installed the latest Linuxcnc (2.5) version using the 10.04 live cd.

Everything installed correctly
Max Latency reported around 6000

I have a four axis stepper motor setup that I have been using for years without problems.

Went trough Stepconf (see attached files) and when I test an axis (any of the four axis) i always get the same result

One direction works flawlessly, but i get no movement whatsoever in the reverse direction.

All attemps so far at tweaking timing or signal direction(normal, inverted) always give the same result and all axis willonly move in one of the two direction (the same direction regardless of software and parallel port settings).

I have also included the manual that came with my stepper drives.

Any help, suggestion, toughts would be greatly appreciated.

Regards

Jacques Blain

your configuration is wrong , your reseting the parrallel port pins ,
i cannot see the reason for this reset in your setup , remove the reset and you should be ok

what is happening your setting say the direction pin low , then switching it back to default high , so therfore the stepper is only going one way
the direction pin is either logic high or low depending on the direction needed , it is not a pulse

Thank you for the info,

You are right, I can see that in the configuration the reset is activated on the parport pins. But I do not know why or how it got set.

I tried simply deleting all configuration files and restarting from scratch by running stepconf again, I got the same configuration, with reset on and was never asked about it.

Am I skipping an important step ?

Should i go in and manually edit the .hal file to remove resets ? I tried but In that case, if I try to run the stepconf test to see if the axis now work in both directions, in that case i still am stuck with my initial problem, because as soon as I start stepconf, it overwrites the hal file, putting back the reset code....

Any suggestions

Regards

Jacques Blain

i notice your reset time is 500 , change to 5000
the reset is as far as i can see only on the step pins , so should be ok ,
use the kelling 4030 preset setttings and see if thats any better

you dont mention which interface to the parrell port you are using ?
check your wiring as Andy suggests .

Hello again,

Did some more testing, always with the same outcome :

In EMC2, Axis moves as expected in the minus direction (when dir signal is high on halscope) and not at all (completely stopped) in the plus direction. I can see the position changing onscreen in both directions.

Electrical connections are as follows and have been traced with an Ohmmeter from the pc port pins on the PC side of my parallel cable, to the terminal screws on the drivers themselves :

Pin 2 XStep
Pin 3 XDir
Pin 4 YStep
Pin 3 YDir
Pin 5 ZStep
Pin 6 ZDir
Pin 7 AStep
Pin 8 ADir

These drivers have a self test mode : do half step half turns of the motor in normal and then reverse direction at about 0.5 hertz. This works fine.

Further more the whole hardware, works fine as is in both directions, when connected to an old setup I had under windows xp...

In my bios, I have different parport mode (PS/2, EPP, ECP) I have so far tried PS/2 and EPP with always the same results

I am stumped. My only thought at this time is to try to find a real scope and monitor the step and dir pins on the drivers ?? Bad part port hardware ?? Software bug ??

I attached my latest config

Thanks for the input guys

Jacques

Hello,

If you do not have a scope you can use a voltmeter on the direction pins of the parallel port , moving one direction should be around 5 volt the other direction 0 volt.

Rick G

these drives are optic isolated so the direction pins may need inverting .