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ASCOM Alpaca Drivers

The Trevinca observatory controller provides two ASCOM Alpaca interfaces:

  • Dome
  • Safety Monitor

The dome only supports the OpenShutter command. The dome cannot be closed via ASCOM Alpaca and will close automatically once conditions become unsafe.

For automation in NINA, it is important to connect both interfaces (and not the cloud watch safety monitor), as this Safety Monitor has some extra conditions before considered safe. Continuing to use the old safety monitor can cause NINA to become confused, because the roof might not be guaranteed to open (in case of admin lock, for example).

Each observatory has its own endpoint. In the examples below, substitute the IP address for your observatory:

ObservatoryAlpaca endpoint

You must have at least ASCOM Platform 6.6 SP1 installed.


  1. Start ASCOM Diagnostics
  2. Choose Device → Choose and connect to device
  3. In the “Device Connection Tester” screen, select Device Type → Select “Safety monitor” and click on the Choose button.
  4. Click on “Alpaca” → “Create Alpaca Driver (Admin)”
  5. Fill in “Trevinca Safety Monitor” and click OK. You should now see this screen:
  6. Then, click on “Properties”
  7. Fill in the observatory IP address and port (always 1880). Disable rediscovery and select “manage connect/disconnect locally”. Leave the rest of the settings as-is:
  8. We have now added the safety monitor. We go back to the “Device Connection Tester” screen, and we select “Dome” and again click on “Choose”.
  9. Click on “Alpaca” → “Create Alpaca Driver (Admin)”
  10. Fill in “Trevinca Roof” and click OK. You should now see this screen:
  11. Click on Properties again and fill out the information. The data that should go into the form is exactly the same as during the safety monitor step:
  12. Now that we have both drivers configured, we can quit the ASCOM diagnostics and we can connect in NINA:

Congratulations, you can now use the Safety Monitor and Dome (roof) in your NINA sequences!