I have the following Setup:
DMC-2143 = SDM-20640 + 3-axis motion stage (X,Y,Theta) stepper motors (no encoders).
It is communicating through RS232 and i can send it commands through GalilTools terminal window without a problem.
The problem is getting repeatable results. For example, if I send a command to move one motor x number of steps, sometimes it gets there, sometimes it stops midway. I would say 30-40% success rate and when it fails to get to the commanded destination, the position error can be up to or even more than 50% of target move. BTW, I have the same slew rate, accel & decel set for each move command.
Anybody have any ideas as to why this is happening?
Any help would be greatly appreciated.
-James
Galil_AndyH on 11/17/2011 - 14:50
James,
Your stepper motors are likely stalling. Try lowering your acceleration, deceleration and speed settings to see if your repeatability increases. Post back your results.
EngineerJames on 11/18/2011 - 07:51
I ran a series of tests to adjust one parameter (accel, decel, speed).
There does not seem to be a pattern as to when it works and when it doesn't.
I tried different combinations... ie. high accel/decel with low speed, low accel/decel with low speed, etc.
I am using 3 stepper motors, PK245-01BA by Oriental Motors Corp, 2 mounted on the Velmex x-slide and one on the Velmex Rotary table B5990TS.
Any other suggestions?
Thanks in advance.
Galil_AndyH on 11/18/2011 - 09:10
Make sure that you have your axes setup for stepper mode
MT*=? should return a 2, -2, 2.5 or a -2.5 for every axis that is in stepper mode.
If you are still having problems e-mail support@galilmc.com
EngineerJames on 11/18/2011 - 12:28
As you suspected,
there was noise on the limit switch lines.
I pulled the limit switch connectors off and set CN to -1
in the program. it's been working well so far.
Thanks for your help.