I am trying to set up a  Syil M4 machine. Its BOB requires a charge pump, but its on pin 9. If I run with the parallel port it works fine, but if I insert the USB SS it will not run.

Is there a problem with using pin 9?

Anyone have a Syil M4 working?

You are using the same profile and just switching the motion control device? Have you checked to see if a signal is coming out of pin 9 on the SmoothStepper? If you don't have an oscilloscope you can use a voltmeter. When the charge pump signal is off you should read zero or five volts and when it is running you will read about 2.5 volts.

I've seen a few strange problems in the past where a corrupt profile caused external motion devices to work one way and the parallel port a different way. One test is to start a profile from scratch and see if that changes things.

why is this function called "Charge Pump?"

The circuit uses a pulse stream to charge a capacitor. If the pulse stream stops the circuit switches the drivers off. Its kind of like the pulse keeps 'pumping' a charge into the capacitor.

Its done this way as a safety- there is no way Mach could keep doing the regular pulse if it has crashed or 'gone nuts' in some way. If the enable was simply a signal, either on or off, it could fail with the signal in the safe state, but mach could be totally dead.

The circuit uses a pulse stream to charge a capacitor. If the pulse stream stops the circuit switches the drivers off. Its kind of like the pulse keeps 'pumping' a charge into the capacitor.

Its done this way as a safety- there is no way Mach could keep doing the regular pulse if it has crashed or 'gone nuts' in some way. If the enable was simply a signal, either on or off, it could fail with the signal in the safe state, but mach could be totally dead.

Ah Huh... Roger that. Makes sense. RC discharge circuit. Thank you.