Paul wrote:
The big problem is the software that reads the G & M codes off the hard
disk, sends the proper commands to the motion control card and generates
the user interface on the LCD and PC keyboard. Do you have something in
mind for
that. Seems that software would be custom for each motion control card
design. Can that be bought off the shelf for some motion control
chips set?
Mark Wrathall wrote:
That's why it is cheaper to dump the motion control cards on Ebay, and buy
Gecko's. Both the Stepper (G210)and Servo (G320) geckos accept step and
direction input from a parallel port. There are about a dozen software which
convert G and M code to step and direction conmmands. TurboCNC (DOS), MACH2
(WIN XP) and EMC are the three best choices (from the CAD_CAM_EDM_DRO
group).
EMC can also be set up with the servo-to-go cards if you want true closed
loop control. In practice the G320 version is fine (PC sends open loop
STEP/Dir commands - Gecko controls the servo's closed loop to acheive that -
Gecko's fault out and report to the PC if the command can't be met (not
likely).
Note the G & M code is not really standardized. The 1974 RS-274 (?) standard
is not adhered to. Obviously EG, on a Rapid (G00) one controller might clear
Z first, and then do a coordinated X, Y move, another controller (like
TurboCNC) might do a coordinated move in all three axis, and a third
controller might send all axis off at their own topspeed. Whatever
Controller SW you end up with you need to be sure that your CAM program has
a Post processor to output your dialect of G code.
The PC based controller mentioned above are generally better at sticking to
the mainstream defacto standard (FANUC) then many OEM controllers.
Regards,
Mark
Something I still don't understand Mark. My servo amps require +/- 10 Volt
analog control signals. How do you get that out of a parallel port?
Paul Lamar
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