mblaszkiewicz wrote: I posted the wiring out diagram. As for a charge pump, I have no idea what that is. Sorry.
That's fine. I was hoping to prompt an internet search which would lead to much more (and better) info that I could type in an evening.
A charge-pump is an an attempt to address the problem of what happens if the PC freezes and leaves all the outputs at the state they were.
If an axis is running at full speed, and you hold that command, while all the feedback control, limit switches, everything else, is dead, then bad things happen. Quickly.
Interestingly step-dir drives have an implicit charge-pump in their operation.
The worry for an +/-10V system driven by PWM is that the PC might freeze with the PWM pin high.
So, a charge-pump circuit is something that turns off power if the input holds a constant value, rather than oscillating as expected. A Watchdog is a digital version of the same idea. if the watchdog code doesn't see the input change for longer than the specified time, it triggers a shutdown.
The various hardware interface cards supported by LinuxCNC typically have a watchdog. If they don'e see a read/write cycle from HAL for more than a few mS they shut down . An actual charge-pump circuit can be used to control a relay in the e-stop chain.
www.cnczone.com/forums/gecko-drives/4093...ge-pump-circuit.html
has some info and links.
