“I am adding this because I believe this is a significant ASIAIR 3.0 issue affecting Sky-Watcher Wave 100i/150i users.”
ASIAIR Plus + Sky-Watcher Wave 150i — Incorrect Home/Park Position, 90° RA Error and Meridian Flip Problems
I am reporting a serious and repeatable issue when using an ASIAIR Plus with a Sky-Watcher Wave 150i mount.
I want to make one point absolutely clear from the beginning:
The Wave 150i itself is functioning correctly.
When I disconnect the ASIAIR and control the mount directly through the Sky-Watcher/SynScan application, the mount performs Auto Home correctly and consistently. The physical Home position is correct.
The problems appear when the ASIAIR takes control of the mount.
- Incorrect Home position / 90° RA error
I have experienced situations where the ASIAIR does not correctly understand the actual position of the mount.
In one particularly clear incident, the mount was physically in its correct Home position, but the ASIAIR treated the position as being approximately 90 degrees (6 hours of RA) different.
This is not a small pointing error. It is a fundamental disagreement between the mount's actual position and the position understood by the ASIAIR.
- Meridian Flip problem
The problem became especially obvious when the mount reached the meridian.
The ASIAIR initiated the process where the mount should move to the opposite side of the meridian, but the Wave 150i did not end up on the correct side.
The mount remained on the same side instead of performing the expected movement.
This makes unattended imaging unreliable because I cannot trust the ASIAIR to correctly determine the mount's RA position and pier side.
- ASIAIR Park does not reliably return the mount to the actual physical Park/Home position
This is, in my opinion, an even more serious problem.
Because the Wave 150i does not have physical markings indicating its Park position, I placed my own physical reference marks on the RA and DEC axes.
After finishing an imaging session, I used the ASIAIR's Park function.
I then checked the physical position of the mount against my reference marks.
I found that the ASIAIR did not always return the mount to the same physical Park position.
I have observed an error of at least approximately 1 degree on RA, and on other occasions approximately 1 degree or more on DEC.
This is extremely concerning.
If the ASIAIR leaves the mount one degree away from the real physical Home position after one session, there is no guarantee that the accumulated positional error will not become larger in subsequent sessions.
- The workaround
I have found a workaround which strongly suggests that the problem is related to the ASIAIR's handling of the mount position/Home state.
My procedure is:
- Power off the Wave 150i and ASIAIR.
- Power on the Wave 150i without the ASIAIR.
- Connect to the mount using the Sky-Watcher application.
- Perform Auto Home.
- Disconnect from the Sky-Watcher application.
- Power off the mount.
- Power on the mount again together with the ASIAIR.
- Connect the ASIAIR to the mount.
After doing this, the ASIAIR can then correctly control the mount and GoTo can work normally.
This workaround is currently necessary because I cannot trust the ASIAIR to establish the correct mount position by itself.
However, this means that I effectively have to perform this procedure before every new imaging session.
- Firmware versions
The problem was present with ASIAIR firmware version 2.5.2 and is still present with the current ASIAIR 3.0 version.
Therefore, this does not appear to be a problem that was resolved by the transition from 2.5.2 to 3.0.
- My main concern
I purchased the ASIAIR specifically because it is advertised and designed to make astrophotography simpler and easier.
Instead, with the Wave 150i, I currently have to:
- manually Auto Home the mount through SynScan,
- disconnect SynScan,
- power-cycle the mount,
- then start the ASIAIR,
- and hope that the ASIAIR now correctly understands the mount's position.
Furthermore, I cannot reliably trust the ASIAIR Park function to return the mount to its actual physical Park position.
This defeats one of the main reasons for using an ASIAIR in the first place.
I previously used N.I.N.A., and although N.I.N.A. requires more configuration, I am now finding the ASIAIR workflow unnecessarily complicated because of this issue.
- Questions for ZWO
I would appreciate a specific technical answer to the following questions:
Is the incorrect Home/Park position and RA/DEC synchronization with the Sky-Watcher Wave 100i/150i a known ASIAIR issue?
Is ZWO currently working on a firmware fix for this problem?
If it is a known limitation rather than a bug, why does ASIAIR not provide a way to manually define or synchronize the actual Home Position of the mount?
Can ZWO implement a reliable way for ASIAIR to obtain and maintain the actual RA, DEC and pier-side state from the Wave 150i rather than relying on an incorrect internal position state?
Can the Park function be corrected so that it reliably returns the Wave 150i to the same physical Home/Park position?
Most importantly: Can you provide a clear indication of whether this issue is expected to be fixed in a future ASIAIR firmware release?
I am not asking for troubleshooting suggestions concerning the mechanical condition or firmware of my Wave 150i.
The mount performs Auto Home correctly when controlled independently through SynScan. The problem occurs when the ASIAIR is responsible for determining and controlling the mount's position.
I would therefore appreciate this being treated as an ASIAIR mount-control/position-synchronization issue, rather than as a generic mount setup problem.
I really like the concept of the ASIAIR and the simplicity it is supposed to provide. However, I need to be able to trust the system with an unattended imaging session. At the moment, with the Wave 150i, I cannot reliably trust its Home position, Park position or Meridian Flip behavior.
I would therefore appreciate a concrete answer from ZWO regarding this issue and whether a firmware fix is planned.
