Originally Posted by
bbutcher85710
That may all be true with Mach3 using the parallel port. However according to Galil documentation (DMC1700-1800 User Guide) the Optima board captures the encoder position within 25 micro seconds of contact. From the users guide:
"Often it is desirable to capture the position precisely for registration applications. The DMC-
1700/1800 provides a position latch feature. This feature allows the position of the main or auxiliary
encoders of X,Y,Z or W to be captured within 25 microseconds of an external low input signal. The
general inputs 1 through 4 and 9 thru 12 correspond to each axis."
This encoder position is reported to Mach3 by the plugin. The accuracy of the location will be a function of the speed of course. For my system I move at a rate of 4 inches per minute, or 0.066 inches per second. Thus a delay of 25 microseconds will result in an error of positon of 0.000000066 inches, which is far better than Mach3 can resolve. .
This is another advantage of using a dedicated processor to handle the motion, but it does make the configuration a bit more messy. All PID motor tuning is also handled by the Optima board, and must be done outside Mach3.