Telescope Commands
Below are the telescope mount commands. All of these commands, except telescopesetup require the TELESCOPE variable to be set to the name of an ASCOM telescope driver.
The command telescopeon must be used before any other telescope command can be used.
All commands set the boolean variable TELESCOPEERROR to "true" if an error occurs or "false" if no error occurs. If an error occurs, the variables TELESCOPEERRORNUMBER and TELESCOPEERRORMESSAGE are set to the values provided by the ASCOM driver.
- telescopesetup
- telescopeon and telescopeoff
- park and unpark
- setpark
- trackingon and trackingoff
- findhome
- goto and gotoasync
- gotoradec and gotoradecasync
- gotowait
- abortslew
- sync and syncradec
- guide
- setoffsettrackingrates
- setguidingrates
- getradec
- getazalt
- getsideofpier
- getdestinationsideofpier
- gettracking
- getparked
- getslewing
- getguiding
- gethomed
- nativecommand
telescopesetup
Syntax: telescopesetup
This command displays the ASCOM telescope setup dialog box. From this dialog box, the user can select a specific ASCOM telescope driver and set its parameters. The selected driver is saved to the TELESCOPE variable and becomes the active telescope used by ARAP.
telescopeon
Syntax: telescopeon
This command initiates communication with the telescope. If this operation is successful, the variable TELESCOPECONNECTED is set to "true". After the telescope is connected the variable EPOCH is set. All commands that require communication with the telescope must be preceded by this command.
telescopeoff
Syntax: telescopeoff
This command terminates communication with the ASCOM telescope and sets the variable TELESCOPECONNECTED to "false".
park
Syntax: park
This command, depending on the telescope's capability or driver settings, moves the telescope to its predetermined park position and stops the right ascension drive. Note that some telescope models stop communicating after this command is issued and requiring them to be powered off and on before they will respond.
unpark
Syntax: unpark
This command, assuming the telescope is so capable, unparks the telescope and may start the right ascension drive depending on the telescope model. Note that some telescope models don't actually start their drive until after the first "goto" operation or until the trackingon command is issued.
setpark
Syntax: setpark
This command, assuming the telescope is so capable, sets the telescope position for subsequent park commands.
trackingon
Syntax: trackingon
This command, assuming the telescope is so capable, starts the right ascension drive.
trackingoff
Syntax: trackingoff
This command, assuming the telescope is so capable, stops the right ascension drive.
findhome
Syntax: findhome
This command, depending on the telescope's capability, finds the telescope's home position.
goto
Syntax: goto objectname <delay>
This command searches the object databases for "objectname", enables tracking, and moves the telescope there. The telescope can be moved to a specific position by using the format "#RA,DEC". The optional "delay" parameter causes a delay (in integer seconds) after the telescope has been moved. The variables RA, DEC, and FINDERROR are set accordingly. The telescope is given a maximum of five minutes to complete its slewing.
gotoasync
Syntax: gotoasync objectname
This command searches the built-in object databases for "objectname", enables tracking, and starts moving the telescope there. The telescope can be moved to a specific position by using the format "#RA,DEC". The variables RA, DEC, and FINDERROR are set accordingly.
gotoradec
Syntax: gotoradec <delay>
This command enables tracking and moves the telescope to the position specified by the RA and DEC variables. The optional "delay" parameter causes a delay (in integer seconds) after the telescope has been moved. The telescope is given a maximum of five minutes to complete its slewing.
gotoradecasync
Syntax: gotoradecasync
This command enables tracking and starts moving the telescope to the position specified by the RA and DEC variables. The variable FINDERROR is set accordingly.
gotowait
Syntax: gotowait <delay>
This command waits for the completion of a prior gotoasync or gotoradecasync command. The optional "delay" parameter causes a delay (in integer seconds) after the telescope has been moved. The telescope is given a maximum of five minutes to complete its slewing.
abortslew
Syntax: abortslew
This command aborts the current telescope slew operation.
sync
Syntax: sync objectname
This command searches the object databases for "objectname" and then synchronizes the telescope's position. The telescope can be synced to a specified position by using the format "#RA,DEC". The variable FINDERROR is set accordingly.
syncradec
Syntax: syncradec
This command synchronizes the telescope's position to the . The telescope can be synced to a specified by the RA and DEC variables.
guide
Syntax: guide direction duration
This command starts a guiding motion in the specified "direction" (0 is north, 1 is south, 2 is east, 3 is west) for a specified "duration" in milliseconds (up to 10,000 - equivalent to 10 seconds). Use getguiding to determine when the operation is finished.
setoffsettrackingrates
Syntax: setoffsettrackingrates deltara deltadec
This command alters the telescope's tracking rates relative to the default rate (usually sidereal rate in right ascension and no motion in declination). The units used are arc-seconds per minute and values up to plus or minus 1,080,000 arc-seconds/minute (equivalent to 5 degrees per second) are allowed. The right ascension rate is corrected for the telescope's current declination. This command if typically used to track moving objects such as comets, asteroids, or the Moon.
setguidingrates
Syntax: setguidingrates rarate decrate
This command sets the guiding rates used by the guide command. The units used are arc-seconds per seconds and values up to 18,000 arc-seconds/second (equivalent to 5 degrees per second) are allowed.
getradec
Syntax: getradec
This command queries the current equatorial position of the telescope and sets the variables RA and DEC.
getazalt
Syntax: getazalt
This command queries the current local horizon position of the telescope and sets the variables AZ and ALT.
gettracking
Syntax: gettracking
This command queries the current state of telescope tracking and sets the variable TRACKING to a boolean value.
getparked
Syntax: getparked
This command queries the current "parked" state of the telescope and sets the variable PARKED to a boolean value.
getsideofpier
Syntax: getsideofpier
This command queries the telescope and sets the variable SIDEOFPIER as follows:
- true - telescope is on west side of pier looking east
- false - telescope is on east side of pier looking west
This command is generally only relevant for German Equatorial telescopes and you must be using a V2+ ASCOM driver.
getdestinationsideofpier
Syntax: getdestinationsideofpier
This command is used to predict which side of the pier the telescope will be on for a "goto" to position in variables RA and DEC. The variable SIDEOFPIER is set as follows:
- true - telescope is on west side of pier looking east
- false - telescope is on east side of pier looking west
This command is generally only relevant for German Equatorial telescopes and you must be using a V3+ ASCOM driver.
getslewing
Syntax: getslewing
This command queries the current "slewing" state of the telescope and sets the variable SLEWING to a boolean value.
getguiding
Syntax: getguiding
This command queries the current "guiding" state of the telescope and sets the variable GUIDING to a boolean value.
gethomed
Syntax: gethomed
This command queries the current "homed" state of the telescope and sets the variable HOMED to a boolean value.
nativecommand
Syntax: nativecommand blind flag command
This command sends a native “command” (a command string in the native language of the telescope) to the telescope. If “blind” is "true", the command is sent, but a response is not expected or received from the telescope. If “blind” is false, the command is sent and the result is stored in the NATIVERESULT variable. If “flag” is "true", the result is expected to be a boolean (set to "true" or FALSE) otherwise it is expected to be a string.