Question Control unit STG350/STG500

This may sound a bit small but what is the purpose of the Control unit STG350/STG500! Is it rpm control of the spindle only?
Leo

It is the controller of the stepcraft spindle. The spindle is build with a brushless-motor. Those motors don't work on ordinary direct or alterating current. They need some alternating current relating to the rpm.

So, these boxes create the currency needed by the brushless, give you the opportunity of speedcontrol and the difference between 350 and 500 version is the power they can provide.

Thanks ... This is what I though.
Leo

We at PMDX have a customer who wants to interface to this spindle
driver for the HF-500 spindle from a Geckodrive G540 stepper motor
driver. He told us that the driver box has inputs labeled Ground
and PWM. What are the properties of the PWM input? Is it a logic
level input or an analog voltage input? Does it require optical
isolation?

Thanks,
Steve Stallings