Hi,
firstly can your machine do 600ipm. It can go only as fast as you set in the motor tuning page.
In addition the kernel seed may limit the speed you can go.
Lets say you steps/inch are 4000.
600 ipm is equivalent to 10 IPsec, 10x4000=40,000 pulses per sec. If your kernel speed is 25,000 per sec
the your out of luck, you cannot produce enuf pulses in a given time to drive the axis that fast.
Another issue is with co-ordinated motion, if you have one axis which is slow, a motor or driver limitation say, then
Mach will reduce the speed of the other axes to match the slow one if its incorporated in the move.
One last point is to make sure that federate/ rapidrate Overide is not in effect, I've overlooked that before!
Craig