Is there a way to test Mesa 7i76e spindle function?

I replaced the USB based controller in a 6040 with a Mesa 7i76e and am using pncconfig to configure it. The X, Y and Z steppers seem to work correctly. The spindle works if I change the VFD to local control and turn the dial. It speeds up and down as expected.

But I been unable to get the spindle to turn when I set the VFD back to computer control and try to configure it with pncconfig.

Is there a way to see if the 7i76e TB4 connections are working correctly and that it's not defective or more likely that I somehow damaged it?

I know just enough to be dangerous.

If the 7I76E is connected to the VFD properly, you should be able to measure
+10 from TB4 pin 3 to TB4 pin 1. Then if you vary the spindle speed in LinuxCNC
the voltage from TB4 pin 2 (+) to TB4 pin 1 (-) should vary with the commanded
spindle speed.

Would it also be possible to use a 2k2 across the 7i76e terminalsTB4 Pin1 & TB4 Pin2 and measure with a multimeter, without it being connected to the VFD ?

You don't need a load but you do need a 5V to 15V supply from TB4 pins
3 (+) to 1 (-). VFDs usually supply 10V (potentiometer power)

Both readings seem correct so it's back to my wiring. At least now I know I am not wasting time on a damaged card.

Thank you.