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« on: December 20, 2017, 06:23:08 PM »
Hi,
Mach is not a hugely CPU thirsty program. What Mach requires is CONTINUOUS CPU service, if the CPU for whatever
reason stops to do something else then Mach will stall and usually stop.
External motion controllers are better for maintaining continuous service than a parallel port.
If you have a servo with a 10,000 count encoder, the current entry level incremental encoder, and you want the servo to
do 50 revs/sec max, that is 3000 rpm, then Mach would have to issue 50 x 10,000=500k pulses per second.
Machs parallel port is commonly capable of 25k and if you push it might get some PCs to produce 100k, not particularly
reliably but still 100k. This is still FIVE times short of whats required to drive a decent servo at max speed and max resolution.
Some external motion controllers can manage that speed but would absolutely require differential signalling. Be careful for
what you wish for....more pulses can also mean more headaches.
Craig