Hi Bob, thanks for the excellent word of wisdom. The system is up and running fine now. The issue was the mount design and lack of documentation from the manufacturer. The IOPtron HAE69EC is actually a very clever design with some out of the box thinking. The documentation was written for the hand controller but paid scant attention to the Commander software which is also the ASCOM interface. Unlike every other mount I've worked with the HAE69EC (a strain wave mount with an unbalanced payload capacity of 70 pounds) has reprogrammable "Home" settings. These home settings, called "Zero Position" in IOPtron terms are not fixed hardware locations such as PlaneWave or Bisque use. For those mounts home is always in exactly the same spot. With the IOPtron, these locations for RA and Dec may be changed by the user. These are set by the factory in default locations that may be good enough - or maybe not. My mount had an error of some 70 arc minutes - enough to trip up Pinpoint which sent plate solves to an all sky plate solver. By the way, I did get ansvr working as advertised. ACP's pointing model was good enough to correct to about a 5 arc minute error.

But why the large 70 arc-minute error to begin with? The mount was exactly level. The polar alignment with iPolar was perfect. It turns out that the default Zero position was incorrect.

Here is the simple fix - Home the mount by first Search Zero Position and then Goto Zero Position. Then slew to a bright star that is easily identifiable. Alcyone fit the bill perfectly with a cluster of easily identifiable stars nearby. After slewing to the star, capture a short image. Plate Solve that image (if the target is not visible in the image). The difference between the image center and the star location will tell you which way to jog the mount (remember to keep tracking on) to center the target. When the target star is centered use the Sync to Target command (whose explanation is exactly the opposite of what it actually does). The slew the mount back to the Zero Position. To get to the Zero Position the mount simply backtracks the previous slew distance in RA and Dec. It does NOT go to the old Zero Position. Instead it goes to a new Zero Position informed by the Sync to Target command. The Zero Position menu contains a command to Set Current Position as Zero Position. Do that. The mount now has a new programmed Home or Zero Position! To check the work go back to the target star, plate solve - and you will find that it is within a few arc-minutes now. Easily digestible by Pinpoint. Even with a huge error in homing ACP still provided usable images with recentering after each image.

Case closed!

John