Recommend me a servo amplifier / driver / h-bridge

Andy,

Thanks, I got it working (sort of - need to sort reverse speed).

Omron G6S-2F 12V relay - DPDT relay
Wiring:
SPINDIR+ = 12V
SPINDIR- = Relay coil +
Flyback diode across relay coil

One pole of relay has:
NC - SPINDLEOUT
NO - Ground

Other pole has
NC - Ground
NO - SPINDLEOUT

Relay outputs are connected to Copley 422 amplifier REF+ and REF-



Problem at the moment is that forward works at the correct speed, but reverse does not get to full speed. I'm sure this is a software problem, as when I invert the SPINDIR in HAL, reverse works at full speed and forward does not get to full speed, therefore it isn't a motor / amplifier problem.

Make sure you use the absolute spindle speed command (negative numbers for spinout will cause problems)

I am using the absolute speed command.

I have tracked the problem further, it appears to be due to single ended signal into the differential input on the drive.

Measured at the servo amplifier input:
REF+ grounded, and REF- supplied 10V results in full speed
REF+ supplied 10V, and REF- grounded results in about 800rpm which then drops to about 700rpm.