Hi,
Mach3's parallel port has by default a kernel frequency of 25kHz. With a well behaved PC you might be able to increase that to 45kHz or maybe 65kHz, or with an extremely
well sorted PC 100kHz.
The kernel frequency is the maximum pulse rate the parallel port can produce. In the case of a default installation that is 25kHz. Lets also guess that your servo requires 10,000
pulses to turn one revolution. At a max pulse rate of 25kHz then the servo could rotate only 2.5 revolutions per second or 150 rpm. As you can see the kernel frequency limits what the servo can do.
What is the encoder resolution of your servo? Is it programmable, ie have 'electronic gearing'. If so you need to set it to about 500 pulse per revolution. The at 25kHz pulse input:
25,000 / 50 =50, so the servo could do 50 revolutions per second or 3000rpm.
According to the manual the lowest resolution you can get with the servo is 1600 pulse/rev. With a pulse rate of 25kHz:
25000 /1600 =15.625 revs/sec or 937 rpm. With a default parallel port installation this is as fast as you could expect for a Step/Direction driven servo.
You either have to increase the kernel frequency to 65kHz or more, possible but commonly fraught with difficulties, PCs just don't like it OR get an external motion controller like a UC100 (max frequency 100kHz)\
or an ESS (max frequency 4MHz).
Craig