Imaging west of meridian question

Psy1280

Rookie question: If I want to start imaging west of the meridian, after polar aligning, if I slew to the target, does the ASIAIR do a meridian flip? If not how do I tell the AIR to flip?

w7ay

Psy1280 if I slew to the target, does the ASIAIR do a meridian flip?

The ASIAIR does not perform Meridian Flips; the mount executes a Meridian Flip when it is sent a GOTO command that causes it to change the pier side (i.e., a GOTO that crosses the Meridian,or more precisely, the Meridian offset in the mount).

So, a slew from ASIAIR will not cause a meridian flip. Only a GOTO command will.

Do not ever move the mount past the Meridian using a slew command, or the mount may mistake its pier side from that point onwards -- this is why for most mounts that do not have absolute encoders, you want to religiously home the mount immediately after an ASIAIR Polar Alignment (a home command will also reset the pier side in the mount), since the ASIAIR polar alignment process includes a "60º" slew that could change the pier side of the mount. Once the correct pier side is lost, any subsequent GOTO will cause the mount to move in the opposite direction (you read about this mistake a lot on this forum).

Chen

enaiman

Psy1280 If the target you are going to is already past meridian the scope will simply go there, there is no meridian flip involved, just a simple GoTo.
Meridian Flip applies when a target is tracked before meridian and continues to be tracked after meridian - that is when the mount needs to perform a Flip in order to continue tracking.