Telescope Interface Standard 2.0Programmer's Reference
Telescope Interface Standard 2.0This specification covers a simple, low-level telescope control interface for reading and writing coordinates, slewing, synchronizing and access to common controller functions. It does not provide for accessories such as focusers, flip mirrors, etc. Those sorts of things will have their own interfaces. The characteristics of this interface comply with the ASCOM Quality Guidelines, assuring consistent behavior and compatibility with the widest possible variety of Windows Automation clients.
In addition to containing features, the 2.0 specification has been clarified in numerous areas. These changes appear with this background color when they apply to existing V1 properties and methods. New properties and methods in V2.0 are not marked with the change color. For a summary of the changes and additions since the previous standard (Telescope 1.4), please refer to the Release Notes.
All of the methods and properties specified must be present in any conforming driver's interface. However, some methods and properties may not actually be implemented; they will raise a "not implemented" error when called or accessed.
Equatorial coordinates are in the system specified by the new EquatorialSystem property (usually local topocentric, and depending on the mount), hours for right ascension, and degrees for declination. Thus, "inner loop" issues such as mechanical compensation must be contained within the driver or it's underlying controller(s). Time is in Coordinated Universal Time (UTC).
To control a particular telescope type, a program would create an instance of the driver for that telescope type, then use the standard properties and methods described in this document to effect control of that scope. Thus any program or script that uses the standard driver interface automatically gains access to any telescope type for which a driver exists. For more information on ASCOM, see the ASCOM Home Page.