Gemini Serial Interface Command Description

Gemini Serial Interface Command Description

The Gemini system supports a subset of the Meade® LX200 Command Set, with some extensions added.

Syntax: values in <> are (to be) replaced by actual values. Curled brackets {} show alternative characters.
Upon completion, ASCII characters or strings are returned.

Command Returns Remarks

0x06 (ACK char) G# Usable for testing the serial link and for determining the type of mount (German equatorial).

Synchronize

:CM# No object!# or
<object name># The string "No object!#" is returned if the mount is not aligned or no object was selected, otherwise the name of the object used is returned.
In Level I, this command does an "Additional Alignment", (re)calculating the pointing model parameters and synchronizing to the position given.

Get Information

:GC# <mm>/<dd>/<yy># UTC Calendar Date, month mm, days dd and years yy separated by slashs.

:GD# In High Precision mode:
{+-}<dd>:<mm>:<ss>#
In Low Precision mode:
{+-}<dd>°<mm># Apparent (refraction included) Declination the telescope is pointing to, to the equinox of the date. Despite during GoTo operations, the coordinates are corrected according to the pointing model.
Signed degrees (-90 to +90), minutes, seconds. The degree sign in Low Precision mode is the character 0xDF.

:GL# <hh>:<mm>:<ss># UTC time from the internal Real Time Clock, hours, minutes, seconds in 24-hour format.

:GR# High Precision mode:
<hh>:<mm>:<ss>#
Low Precision mode:
<hh>:<mm>.<m># Apparent (refraction included) Rectascension the telescope is pointing to, to the equinox of the date. Despite during GoTo operations, the coordinates are corrected according to the pointing model.
Hours (0 to 24), minutes, seconds or tenth of minutes.

:Gc# (24)# Clock format

:GV# <l><vv># Get Software Level l (one digit) and Version vv(two digits)

Move Telescope Note: the directions mentioned are depend upon the hemisphere of the observing site and the side of the mount the telescope actually is. Directions do not change when crossing one of the poles.

:MS# 0
1Object below horizon.#
2Telescope is not aligned.#
2No object selected.#
3Manual Control.# Slew to the selected object. Selection is done locally or by sending the Sr and Sd command. This commands will be rejected if the system is in Manual Mode, f.i. Identifying or selecting an object from the internal databases.

:Me# Move eastwards at Centering Speed (in Visual Mode) or Guiding Speed.

:Mw# Move westwards at Centering Speed (in Visual Mode) or Guiding Speed.

:Mn# Move northwards at Centering Speed (in Visual Mode) or Guiding Speed.

:Ms# Move southwards at Centering Speed (in Visual Mode) or Guiding Speed.

Object/Observing

:ON<name># Tells the Gemini system the name or identification of the selected object. If this command is not used, the name defaults to "PC Object". Using this command is recommended.

Precision

:P# HIGH PRECISION
or
LOW PRECISION Both strings are 14 characters long (there are 2 blanks between LOW and PRECISION).

:U# Toggle between Low Precision (short) and High Precision (long) mode. The system is in High Precision mode after starting up.

Quit Moving

:Q# Quit all movements mentioned below.

:Qe# Quit movement eastwards.

:Qw# Quit movement westwards.

:Qn# Quit movement northwards.

:Qs# Quit movement southwards.

Set

:SC<mm>/<dd>/<yy># 0 if invalid or
1Updating planetary data#
<24 blanks># Set Calendar Date: months mm, days dd, year yy of the civil time according to the timezone set. The internal calender/clock uses GMT.

:SG{+-}hh# 1 Hours after (sign +) or before (sign -) GMT. The timezone has to be set before setting the Calendar Date (SC) and Local Time (SL), since the Real Time Clock is running at GMT.

:SL<hh>:<mm>:<ss># 1 Set RTC Time from the civil time hours hh, minutes mm and seconds ss. The timezone has to be set before using this command.

:Sd{+-}<dd>{*°}<mm>#
or
:Sd{+-}<dd>{*°:}<mm>:<ss> 0 if invalid or
1 if valid Sets the object's declination and sets the object status to "Selected". It is important that the :Sr# command has been send prior.

:Sg{+-}<ddd>*<mm># 1 if valid Sets the longitude of the observing site to ddd degrees and mm minutes. The longitude has to be specified positively for western latitudes (west of Greenwich, the plus sign may be omitted) and negatively for eastern longitudes. Alternatively, 360 degrees may be added to eastern longitudes.

:Sr<hh>:<mm>.<m>#
or
:Sr<hh>:<mm>:<ss># 0 if invalid or
1 if valid Sets the object's rectascension and the object status to "Not Selected". The :Sd# command has to follow to complete the selection. The subsequent use of the :ON# command is recommended.

:St{+-}<dd>*<mm># 1 if valid Sets the latitude of the observing site to dd degrees, mm minutes. The minus sign indicates southern latitudes, the positive sign may be omiited.

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Command	Returns	Remarks

0x06 (ACK char)	G#	Usable for testing the serial link and for determining the type of mount (German equatorial).

Synchronize

:CM#	No object!# or <object name>#	The string "No object!#" is returned if the mount is not aligned or no object was selected, otherwise the name of the object used is returned. In Level I, this command does an "Additional Alignment", (re)calculating the pointing model parameters and synchronizing to the position given.

Get Information

:GC#	<mm>/<dd>/<yy>#	UTC Calendar Date, month mm, days dd and years yy separated by slashs.
:GD#	In High Precision mode: {+-}<dd>:<mm>:<ss># In Low Precision mode: {+-}<dd>°<mm>#	Apparent (refraction included) Declination the telescope is pointing to, to the equinox of the date. Despite during GoTo operations, the coordinates are corrected according to the pointing model. Signed degrees (-90 to +90), minutes, seconds. The degree sign in Low Precision mode is the character 0xDF.
:GL#	<hh>:<mm>:<ss>#	UTC time from the internal Real Time Clock, hours, minutes, seconds in 24-hour format.
:GR#	High Precision mode: <hh>:<mm>:<ss># Low Precision mode: <hh>:<mm>.<m>#	Apparent (refraction included) Rectascension the telescope is pointing to, to the equinox of the date. Despite during GoTo operations, the coordinates are corrected according to the pointing model. Hours (0 to 24), minutes, seconds or tenth of minutes.
:Gc#	(24)#	Clock format
:GV#	<l><vv>#	Get Software Level l (one digit) and Version vv(two digits)

Move Telescope		Note: the directions mentioned are depend upon the hemisphere of the observing site and the side of the mount the telescope actually is. Directions do not change when crossing one of the poles.

:MS#	0 1Object below horizon.# 2Telescope is not aligned.# 2No object selected.# 3Manual Control.#	Slew to the selected object. Selection is done locally or by sending the Sr and Sd command. This commands will be rejected if the system is in Manual Mode, f.i. Identifying or selecting an object from the internal databases.
:Me#		Move eastwards at Centering Speed (in Visual Mode) or Guiding Speed.
:Mw#		Move westwards at Centering Speed (in Visual Mode) or Guiding Speed.
:Mn#		Move northwards at Centering Speed (in Visual Mode) or Guiding Speed.
:Ms#		Move southwards at Centering Speed (in Visual Mode) or Guiding Speed.

Object/Observing

:ON<name>#		Tells the Gemini system the name or identification of the selected object. If this command is not used, the name defaults to "PC Object". Using this command is recommended.

Precision

:P#	HIGH PRECISION or LOW PRECISION	Both strings are 14 characters long (there are 2 blanks between LOW and PRECISION).
:U#		Toggle between Low Precision (short) and High Precision (long) mode. The system is in High Precision mode after starting up.

Quit Moving

:Q#		Quit all movements mentioned below.
:Qe#		Quit movement eastwards.
:Qw#		Quit movement westwards.
:Qn#		Quit movement northwards.
:Qs#		Quit movement southwards.

Set

:SC<mm>/<dd>/<yy>#	0 if invalid or 1Updating planetary data# <24 blanks>#	Set Calendar Date: months mm, days dd, year yy of the civil time according to the timezone set. The internal calender/clock uses GMT.
:SG{+-}hh#	1	Hours after (sign +) or before (sign -) GMT. The timezone has to be set before setting the Calendar Date (SC) and Local Time (SL), since the Real Time Clock is running at GMT.
:SL<hh>:<mm>:<ss>#	1	Set RTC Time from the civil time hours hh, minutes mm and seconds ss. The timezone has to be set before using this command.
:Sd{+-}<dd>{°}<mm># or :Sd{+-}<dd>{°:}<mm>:<ss>	0 if invalid or 1 if valid	Sets the object's declination and sets the object status to "Selected". It is important that the :Sr# command has been send prior.
:Sg{+-}<ddd>*<mm>#	1 if valid	Sets the longitude of the observing site to ddd degrees and mm minutes. The longitude has to be specified positively for western latitudes (west of Greenwich, the plus sign may be omitted) and negatively for eastern longitudes. Alternatively, 360 degrees may be added to eastern longitudes.
:Sr<hh>:<mm>.<m># or :Sr<hh>:<mm>:<ss>#	0 if invalid or 1 if valid	Sets the object's rectascension and the object status to "Not Selected". The :Sd# command has to follow to complete the selection. The subsequent use of the :ON# command is recommended.
:St{+-}<dd>*<mm>#	1 if valid	Sets the latitude of the observing site to dd degrees, mm minutes. The minus sign indicates southern latitudes, the positive sign may be omiited.