If EQ6 mount is being controlled from Stellarium via ASCOM driver, then if I point the telescope at an object, then turn off the mount, and later turn the mount back on, will ASCOM be able to re-establish pointing position of mount?

Short answer: no — not reliably, and usually not at all.

When you’re using an EQ6 mount (like the Sky-Watcher EQ6-R Pro) through ASCOM Platform and Stellarium, the system does not inherently remember its physical pointing after a power loss.

Here’s what actually happens:

🔌 When you turn the mount off

  • The mount loses its internal state (unless it has absolute encoders — EQ6-class mounts do not).
  • ASCOM and Stellarium only know where the mount was based on tracking data, not actual physical verification.
  • If the mount is moved even slightly while powered off, that positional reference is gone.

🔄 When you turn it back on

  • The mount starts “blind” — it has no idea where it is pointing.
  • ASCOM reconnects fine, but it cannot reconstruct the sky position unless:
    • The mount was returned exactly to a known reference (like home position), and
    • You explicitly tell the software that it is at that position.

⚠️ What if you didn’t move it?

Even if you think nothing moved:

  • There’s still no guarantee of accuracy.
  • Stepper motors don’t provide feedback — the system assumes, it doesn’t measure.

✅ How to recover properly

You have a few options:

  • Park before shutdown
    Use Stellarium/ASCOM to park the mount (usually at home position). On restart:
    • Power on
    • Unpark
    • The system can resume correctly
  • Re-home manually
    Put the mount back to its index marks/home position, then:
    • Sync or reinitialize via ASCOM
  • Plate solve (best method)
    Use imaging + plate solving to:
    • Determine actual pointing
    • Sync the mount precisely
      (This is the most robust method in practice.)

🧠 Bottom line

ASCOM is just a communication layer — it doesn’t track real-world position after power loss. Without encoders or a proper park/home workflow, you must re-establish alignment each session.


By Admin

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