Yep, the connections are labelled as the a-axis, but it's set up as a spindle (and not as a mill-style rotary axis).
The Spindle2 board is a slightly older version of the one you looked at - no real difference except for one less set of output connectors. I do have a Spindle3 card that I will try if I cant get it to work - it will eliminate the possibility of a dud card, if nothing else.
I may have fixed the counter issue. At least, I think so - I wont be entirely confident until I've had a chance to test it out some more.
Setting the index bounce to zero (as per the discussion in this thread:
http://www.machsupport.com/forum/index.php?topic=6069.0) and increasing the device voltage to 12v (giving a signal voltage of ~5v on the output line) seem to have done the trick.
According to the now-hopefully-correct spindle index, my spindle maxes out at 1876 rpm, which makes sense - 2000 pulses/sec from the inverter at the full 10v, a 2-pole motor, divided by the pulley ratio which is just over 2.1
So, I set the pulley speeds to min 30 and max 2000, then ran a spindle auto-config and it completed successfully although giving me a curve that was a bit odd - it hit max rpm by around 50% of the control value, after which increasing the S value had no effect on the spindle speed. So I saved this curve, and now.... I still get the wrong rpm values - S50 commanded gets me 68 rpm actual, and the difference increases with speed - S1000 is actually running at 1579 rpm.
I am now trying to figure this out, so any suggestions welcomed as always.
Rick