20528
« on: January 10, 2009, 08:11:56 AM »
The Index pulse is a feature of most encoders, it is a single pulse per revolution. Often in industrial CNC the index pulse is used in conjunction with a switch to give very accurate homing, the servo drives I use have that feature built in. What happens is when I tell the drive to home it will move the axis until it sees the switch and then it will seek out the index pulse and depending on how things are set up it will either stop there, move a certain amount of endcoder pulses etc etc.
Another use of the index pulse would be if the motor in question is being used as a spindle, the index is then used to give the speed to Mach, however unless you are using a SmoothStepper or similar the index pulse is too short for Mach to see through the parallel port so it is no use. You can lengthen the pulse with electronics to make it usable through the parallel port though.
You mention resolvers, if you have these on your motors then afraid they are no use for Mach, you will have two choices, get a resolver to ttl convertor or just fit an encoder inplace of the resolver (or as well as it)
Hood