Commands effective: 05-07-01 Text modified: 09-24-01
These are the commands associated with version D or KD of the ROM chip in the GTO Control Box. All chips marked C or KC include all commands listed below except Command: :pS#
You can check the version of your chip by opening the cover of the control box. If your chip is not dated at all, it was probably programmed prior to July 1999 and is an early version. The chip versions beginning with “K” are for the 400GTO and 600EGTO mounts shipped after 02-16-00.
These commands are similar to the Meade LX200 protocol:
Command: :Sr HH:MM:SS# or :Sr HH:MM:SS.S# Response: “1”
Defines the commanded Right Ascension, RA. Command may be issued in long or short format regardless of whether long format has been selected. RA specified as DD*MM:SS will also be interpreted properly if greater precision is required, but this is not typically how RA is expressed. This command automatically selects RA-DEC mode. Move and calibrate commands operate on the most recently defined RA if in RA-DEC mode.
Command: :Sd sDD*MM# or :Sd sDD*MM:SS# Response: “1”
Defines the commanded Declination, DEC. Command may be issued in long or short format regardless of whether long format has been selected. This command automatically selects RA-DEC mode. Move and calibrate commands operate on the most recently defined DEC if in RA-DEC mode.
Command: :Sa sDD*MM# or :Sa sDD*MM:SS# Response: “1”
Defines the commanded Altitude, ALT. Command may be issued in long or short format regardless of whether long format has been selected. Move and calibrate commands operate on the most recently defined ALT. This command automatically selects ALT-AZ mode, however tracking rate is unaffected.
Command: :Sz sDD*MM# or :Sz sDD*MM:SS# Response: “1”
Defines the commanded Azimuth, AZ. Command may be issued in long or short format regardless of whether long format has been selected. Move and calibrate commands operate on the most recently defined DEC. This command automatically selects ALT-AZ mode, however tracking rate is unaffected.
Command: :SG HH# or :SG HH:MM.M# or :SG HH:MM:SS# Response: “1”
Sets the offset from Greenwich mean time. Command may be issued in any format regardless of whether long format has been selected. Although any 24-hour format is acceptable, only the hours field is typically of interest.
Command: :Sg DDD*MM# or :Sg DDD*MM:SS# Response: “1”
Sets the current longitude. Command may be issued in long or short format regardless of whether long format has been selected.
Command: :St sDD*MM# or :St sDD*MM:SS Response: “1”
Sets the current latitude. Command may be issued in long or short format regardless of whether long format selected.
Command: :SL HH:MM:SS# Response: “1”
Sets the current local time. Command may be issued in long or short format regardless of whether long format selected.
Command: :SC MM/DD/YY#
Response 16 spaces followed by “#”, followed by 16 spaces, followed by “#”
Sets the current date. Note that year fields equal to or larger than 97 are assumed to be 20th century, Year 97 are assumed to be 21st century.
Command: :GG#
Response: HH:MM.M# or HH:MM:SS.S# if long format
Gets the offset from Greenwich mean time. Although typically only hours field is of interest, the return value will standard 24 hour format.
Command: :Gg#
Response: +DDD*MM# or +DDD*MM:SS# if long format
Gets the current longitude.
Command: :Gt#
Response: sDD*MM# or sDD*MM:SS# if long format
Gets the current latitude.
Command: :GL#
Response: HH:MM.M# or HH:MM:SS.S# if long format Gets the current local time in 24 hr. format.
Command: :GS#
Response: HH:MM.M# or HH:MM:SS.S# if long format
Gets the current sidereal time in 24 hr. format.
Command: :GR#
Response: HH:MM.M# or HH:MM:SS.S# if long format
Gets the current Right Ascension.
Command: :GD#
Response: sDD*MM# or sDD*MM:SS# if long format
Gets the current Declination.
Command: :GA#
Response: sDD*MM# or sDD*MM:SS# if long format
Gets the current Altitude.
Command: :GZ#
Response: sDD*MM# or sDD*MM:SS# if long format
Gets the current Azimuth.
Command: :CM#
Response: “Coordinates matched. #”
(there are 5 spaces between “Coordinates” and “matched”, and 8 trailing spaces before the “#”, the total response length is 32 character plus the “#”.
Calibrate mount. Current Right Ascension and Declination become the commanded Right Ascension and Declination respectively if in RA-DEC mode. If in ALT-AZ mode, then the commanded Altitude and Azimuth become the current. This command assumes that the mount has been manually positioned on the proper pier side for the calibration object. This command is ignored if slewing is in progress. This command should be used for initial calibration. It should not be used after the mount has been tracking unless it is known that it has not tracked across the meridian.
Command: :Mn# :Ms# :Me# :Mw# Response: (none)
Command motion in the direction specified (n=north, s=south, e=east, w=west) the currently selected guide or centering rate. Motion will continue until a quit command is issued.
Command: :MS#
Response: “0” if command accepted, (none) if command not accepted, “1Object is below horizon #” if the horizon check is turned on, and the desired object is below 0 degrees altitude. (8 trailing spaces before “#”, 32 total characters plus “#”)
Slew to the most recently defined RA and DEC coordinates in RA-DEC mode, or most recently define ALT and AZ coordinates in ALT-AZ mode. Slewing is performed at the currently selected slew rate. If the horizon check is turned on, and the object is below the horizon, this will be stated, and no slewing will occur.
Command: :Qn# :Qs# :Qe# :Qw# Response: (none)
Stop motion in the specified axis. Note that :Qn# is identical to :Qs#, and :Qe# is identical to :Qw#. Motion is terminated only if it was not started by a slew (:MS#) command.
Command: :Q# Response: (none)
Motion in both axis is stopped, regardless of how the motion was invoked.
Command: :U# Response: (none)
Select long format, valid only for the communication port through which this command is issued, ports are controlled independently. Unlike the Meade definition, though, once long format has been selected it cannot be deselected without powering down the unit. Only the first occurrence of :U# acts upon the port in question. Long format only defines the format of the return strings, Input data (using the set command) will be recognized in any format whether or not long format has been selected.
Command: :B+# :B-# Response: (none)
Incrementally increases (B+) or decreases (B-) reticle brightness. Command to be sent over RS-232 each time a button is pressed to increase or decrease brightness. When the brightness is at the maximum, subsequent :B+# commands are ignored. When the brightness is at the minimum, subsequent :B-# commands are ignored. On power up, the brightness is at the minimum (off). The Meade commands :B0# :B1# :B2# :B3# are not implemented.
Command: :F+# :F-# :FF# :FS# :FQ#
Response: (none)
Advances (F+) or retracts (F-) focus adjust motor on the eyepiece. F+ or F- commands commence adjustment and :FQ# stops it. This works the same way the N-S-E-W keypad works (it may even be an operating mode of the same keys). If :FS# has been issued previously, then the focus adjustment will be slow. If the :FF# command has been issued, then the adjustment will be fast. If neither FF nor FS is specified, the powerup default of FS is assumed.
Command: :RG# :RG0# :RG1# :RG2# Response: (none)
Selects guide rate for the N-S-E-W buttons. Optionally selects 0.25x (:RG0#), 0.5x (:RG1#), or 1.0x (:RG2#). If no index is provided (:RG#), the previously selected guide rate will be used, else the power up default of 0.5x will be assumed by the motor drive. The indexes are extensions of the Meade protocol.
Command: :RC# :RC0# :RC1# :RC2# :RC3# Response: (none)
Selects centering rate for the N-S-E-W buttons. Optionally selects a rate of 12x (:RC0#), 64x (:RC1#), 600x (:RC2#), or 1200x (:RC3#). If no index is provided (:RC#), then the previously selected speed will be used, else the power up default of 64x will be assumed by the motor drive. The indexes are extensions of the Meade protocol.
Command: :RS# :RS0# :RS1# :RS2# Response: (none)
Selects the slew speed used by the telescope move functions. This command has no effect on the use of the N-S-E-W buttons (therefore, :RS# has no effect). The default slew speed is 1200x. Slewing can be done at 1200x (:RS2#), 900x (:RS1#), or 600x (:RS0#). The indexes are extensions of the Meade protocol.
Meade commands:
Command: # Response: (none)
Sending a # clears the input buffer. Advisable to do this before sending the very first command on power up.
Command: :RT0# :RT1# :RT2# :RT9# Response: (none)
This command selects the tracking rate. It selects lunar (:RT0#), solar (:RT1#), sidereal (:RT2#), or zero (:RT9#). The sidereal rate is assumed as a default by the motor drive if nothing is specified. This command has no effect on the use of the N-S-E-W buttons. This command is not in the Meade manual. Zero tracking rate is useful in ALT-AZ mode.
Command: :NS# Response: (none)
This command swaps the functions of the north and south buttons. Subsequent commands :Mn# and :Ms# are affected. This command is not in the Meade manual.
Command: :EW# Response: (none)
This command swaps the functions of the east and west buttons. Subsequent commands :Me# and :Mw# are affected. This command is not in the Meade manual.
Command: :p# :pR# :pP# Response: (none)
This command either invokes PEM record mode (:pR#), invokes PEM playback mode (:pP#), or turns playback off (:p#). The record function will remain active for one full revolution of the worm gear and cannot be terminated. If :p# or :pP# is received during record, it will be ignored. The time required for a record cycle depends upon which mount is used and how much correction is applied. Commands to slew will be ignored during record. Commands to select centering speed will become active only after the record cycle has been completed. When playback is selected, it remains active until turned off. Playback is also temporarily turned off when a command to slew is issued or any of the N-S-E-W buttons are pressed. It is automatically reinvoked when the commanded position has been reached and none of the N-S-E-W buttons are pressed. This command is not in the Meade manual.
Command: :Bd DD*MM:SS# :Br DD*MM:SS# Response: "1"
This command sets the amount of backlash compensation employed each time a servo motor axis reverses direction. Bd sets the backlash of the DEC axis, Br sets the backlash of the RA axis. Resolution of the backlash is in arc seconds. Typically, the degrees and minutes fields are zero to specify the amount of backlash only in seconds. Values of backlash above 00*54:36 may be truncated, depending upon which mount is used (this is a ridiculously large value, typical values should be well under 00*01:00). The default DEC backlash is 00*00:00, the default RA backlash is 00:00:15 (same as 00*03:50). Backlash in either axis will be properly interpreted whether expressed as DD*MM:SS or HH:MM:SS. This command is not in the Meade manual.
Command: :ho# :hq# Response: (none)
This command turns on (:ho#) and off (:hq#) the horizon check. The horizon check, when turned on, is performed when a “go-to” (or :MS#) is issued. If the coordinates define a location below zero degrees altitude, then the string “1Object is below horizon. #” is returned instead of “0”. No compensation of coordinates for atmospheric refraction is made. On power-up, the horizon check is off since it is currently performed in the handheld controller, Digital Sky Voice, and Software Bisque’s TheSky.
Command: :de# :dn# Response: (none)
This command invokes the data feed through function between COM 1 and the handheld controller. The purpose is to allow software and database updates to the handheld controller, through the servo drive, without special connectors. For code downloads, :de# is used to provide transparent communications between COM 1 and the handheld unit with even parity. For database downloads, :dn# is used to provide transparent communications with no parity. Once either command is issued, normal operation (or parity change) can only be resumed by powering down the servo drive. COM 2 cannot be used in the transparent mode. Once the pound sign of the command has been received by the servo drive, all subsequent bytes received from COM 1 or the handheld are reflected to the other. Data received on COM 2 is ignored, and no data is transmitted from COM 2.
Command: :CMR#
Response: “Coordinates matched. #”
(there are 5 spaces between “Coordinates” and “matched”, and 8 trailing spaces before the “#”, the total response length is 32 character plus the “#”.
This command performs a function very similar to the :CM# command with one exception. It does not assume that the user has manually positioned the mount on the proper pier side for the object in view. It assumes that the pier side has not changed since the most recent :CM# or :MS# commands. It allows re-calibration on known coordinates even if the mount has tracked across the meridian. This command should not be used to perform the initial calibration. This command is ignored if slewing is in progress.
Command: :KA# Response: (none)
This command invokes the parked mode. The tracking stops and the motors are de-energized when slewing has completed. The mount will remain parked, even if power is cycled, until a move, quit, calibrate, or park-off command is issued.
Command: :PO# Response: (none)
Park-off. This command un-parks the mount and also restores calibration. To restore proper calibration, the mount must receive date and time (:SC dd/mm/yy# and :SL hh:mm:ss#) prior to receiving the Park-off command. If park-off is received when the mount is not actually parked, calibration error will be introduced. A :CM# command can be used, however, to establish accurate calibration.
Command: :V#
Response: (current servo controller software version number)
This command returns the current servo controller software version (followed by “#”). Software versions prior to B do not return anything since the version command is introduced in version B.
Command: :pS#
Response: “East#” or “West#”
This command returns the side of the pier on which the telescope is currently positioned. It is useful for remote observatories where it is not possible for the viewer to see the mount. Initially, the mount must be manually positioned on the proper pier side for the calibration object and calibrated using the :CM# command. The correct pier side will be returned after subsequent move, recalibrate, park and unpark commands.
RS-232 Port Settings:
Baud Rate: 9600 Parity: none Data bits: 8
Flow Control: none or Xon/Xoff Start Bits: 1 Stop Bits: 1