ASCOM Controller

The ASCOM module enables direct control of robotic telescopes compatible with the ASCOM standard from RIA TOM.

Windows only

ASCOM uses Windows COM (Component Object Model). This module only works on Windows with ASCOM Platform installed.

Requirements

• Windows 10/11
• ASCOM Platform 6.6+
• Telescope ASCOM driver installed
• win32com library (pip install pywin32)

Configuration

In FacilitySettings, enable ASCOM control:

• ascom_enabled: True
• ascom_driver: driver ProgID, e.g. "ASCOM.Simulator.Telescope" for the simulator, or "ASCOM.OptecGemini.Telescope" for a real Gemini mount.

Telescope states

The controller maintains a global state accessible from the API:

State	Description
IDLE	No active session
CONNECTING	Connecting to the ASCOM driver
CONNECTED	Connected, waiting to start
SLEWING	Slewing towards the target
TRACKING	Tracking the target (observing)
ERROR	Connection or movement error
STOPPED	Manually stopped

Control API

Start sequence

POST /scheduler/api/ascom/start/

Starts the execution of scheduled windows. The controller:

1. Connects to the specified ASCOM driver.
2. Waits until the start_time of the first window.
3. Slews to the target (SlewToCoordinatesAsync).
4. Enables tracking.
5. Repeats for each window in chronological order.

Stop sequence

POST /scheduler/api/ascom/stop/

Stops the sequence at the current point. The telescope stops tracking the current target.

Query status

GET /scheduler/api/ascom/status/

Returns the current state in JSON:

{
    "state": "SLEWING",
    "current_target": "SN2024abc",
    "message": "Slewing to RA=10.5, Dec=+45.2",
    "progress": 3,
    "total": 8
}

Internal implementation

The _run_sequence(driver_name, windows) function runs in a background thread to avoid blocking the Django server. State is updated in a thread-safe manner via a lock:

with _status_lock:
    _status["state"] = TelescopeState.SLEWING
    _status["current_target"] = target.name

Manual usage example

from scheduler.ascom_controller import _run_sequence
from scheduler.models import ScheduledWindow
import threading

windows = ScheduledWindow.objects.filter(
    facility__ascom_enabled=True,
    start_time__gte=timezone.now()
).order_by("start_time")

thread = threading.Thread(
    target=_run_sequence,
    args=("ASCOM.Simulator.Telescope", list(windows))
)
thread.start()