LX200 Command Set
Intended for professional programmers, the LX200
Command Set is used to write custom software for
remote operation of the telescope with a personal
computer. Each command is listed in a section
appropriate to its type. Each entry in the command
list includes the command name and any parameters
which must be appended, any values which might be
returned and a description of the command. The
parameters and the return data are shown in a manner
that indicates their format. These formats are
listed below along with examples of how the data
might actually appear, the allowable range of values
and a short description.
This command set is presented here as it appears in the Instruction Manual dated 1996 Ver 0196-2
a. Command Set Formats
HH:MM.T Example: 05:47.4
Range: 00:00.0 to 23:59.9
Hours,
minutes, and tenths of minutes.
sDD*MM Example: +45*59
Range: -90*00 to +90*00
Signed
degrees and minutes (the (*) represents ASCII 223 which appears on the
hand controller
as a
degree symbol).
DDD*MM Example: 254*09
Range: 000*00 to 359*59
Unsigned
degrees and minutes.
HH:MM:SS Example: 13:15:36
Range: 00:00:00 to 23:59:59
Hours, minutes, and seconds.
MM/DD/YY Example: 02/06/92
Range: 01/01/00 to 12/31/99 (see
description)
Month,
day, and year. The two digit year indicates the following: 92 through 99
= 1992 through 1999
and 00
through 91 = 2000 through 2091
sHH Example: -5 Range:
-24 to +24
Signed hour offset.
NNNN Example: 3456
Range: 0000 to 9999
Four
digit object number.
sMM.M Example: -02.4
Range: -05.5 to 20.0
Signed
magnitude value.
NNN Example: 134
Range: 000 to 200
Three
digit object size (minutes).
DD* Example: 56*
Range: 00* to 90*
Higher'
parameter (degrees).
TT.T Example: 59.2
Range: 56.4 to 60.1
Tracking
'frequency'. Info
(missing command set format line in manual)
Example: CNGC1 976 SU DNEB MAG 3.9 SZ 66.0'
Range: n/a
Object
information.
Ok Example: 1
Range: 0 or 1
Status
value returned after setting values. If the value is legal 1 is returned,
otherwise 0 is returned.
b. General Telescope Information
Command ACK (ASCII 6)
Returns A, L, P or G
Gets
alignment status, A for alt-azm, L for land, P for polar, G for German
mount polar.
Command :GR#
Returns +HH:MM.T#
Gets
the current Right Ascension.
A recent mapug post indicated that for the 3.34L ROMS the format is
+HH:MM:SS# for RA
And the format for Declination is sDD*MM'SS#. Thus adding
seconds and arc seconds.
Command :GD#
Returns sDD*MM#
Gets
the current declination.
Command :GA#
Returns sDD*MM#
Gets
the current altitude.
Command :GZ#
Returns DDD*MM#
Gets
the current azimuth.
Command :GS#
Returns HH:MM:SS#
Gets
the current sidereal time.
Command :SS HH:MM:SS#
Returns Ok
Gets
the sidereal time.
Command :GL# :Ga#
Returns HH:MM:SS#
Gets
the local time either in 24 hour (GL) or 12 hour (Ga) format.
Command :SL HH:MM:SS#
Returns Ok
Sets
the local time. NOTE: The parameter should always be in 24
hour format.
Command :GC#
Returns MM/DD/YY#
Gets
the calendar date.
Command :SC MM/DD/YY#
Returns Ok (see description)
Sets
the calendar date.
NOTE:
After the Ok, if the date is valid, two strings will be sent. The first
will contain the message
"Updating
planetary data," the second (sent after the planetary calculations) will
contain only blanks.
Both
strings will be terminated by the (*) symbol.
Command :Gt#
Returns sDD*MM#
Gets
the latitude of the currently selected site.
Command :St sDD*MM#
Returns Ok
Sets
the latitude of the currently selected site.
Command :Gg#
Returns DDD*MM#
Gets
the longitude of the currently selected site.
Command :Sg DDD*MM#
Returns Ok
Sets
the longitude of the currently selected site.
Command :GG#
Returns sHH#
Gets
the offset from Greenwich Mean Time.
Command :SG sHH#
Returns Ok
Sets
the offset from Greenwich Mean Time.
Command :W1# :W2# :W3# :W4#
Returns Nothing
Sets
the current site number.
c. Telescope Motion
Command :Mn# :Ms#
:Me# :Mw#
Returns Nothing
Starts
motion in the specified direction at the current rate.
Command :MS#
Returns 0, 1, or 2 (see description)
Slews
telescope to current object coordinates. 0 is returned if the telescope
can complete the slew,
1 is
returned if the object is below the horizon, and 2 is returned if the object
is below the 'higher'
limit.
If 1 or 2 is returned, a string containing an appropriate message is also
returned.
Command :Qn# :Qs#
:Qe# :Qw#
Returns Nothing
Stops
motion in the specified direction. Also stops the telescope if a slew to
object is in progress.
Command :Q#
Returns Nothing
Stops
a slew to an object.
Command :RG# :RC#
:RM# :RS#
Returns Nothing
Sets
the motion rate to guide (RG), center (RC), find (RM), or slew (RS).
d. Library/Objects
Command :Gr#
Returns HH:MM.T#
Gets
object Right Assension
Command :Sr HH:MM.T#
Returns Ok
Sets
object Right Ascension.
A recent mapug post indicated that for the 3.34L ROMS the format is
+HH:MM:SS# for RA
And the format for Declination is sDD*MM'SS#. Thus adding
seconds and arc seconds.
Command :Gd#
Returns sDD*MM#
Gets
object Declination.
Command :Sd sDD*MM#
Returns Ok
Sets
object Declination.
Command :CM#
Returns (see description)
Sync.
Matches current telescope coordinates to the object coordinates and sends
a string indicating which
object's
coordinates were used.
Command :Gy#
Returns GPDCO#
Gets the 'type'
string for the FIND operation. A capital letter means that the corresponding
type is selected
while a lower
case letter indicates it is not.
Command :Sy GPDCO#
Returns Ok
Gets
the ‘type' string for the FIND operation.
Command :Gq#
Returns SU#, EX#,
VG#, GD#, FR#, PR# or VP#
Gets
the current minimum quality for the FIND operation
Command :Sq#
Returns Nothing
Steps
to the next minimum quality for the FIND operation.
Command :Gh#
Returns DD*#
Gets
the current 'higher' limit.
Command :Sh DD#
Returns Ok
Sets
the current 'higher' limit.
Command :Gb# :Gf#
Returns sMM.M#
Gets
the brighter (Gb) or fainter (Gf) magnitude limit for the FIND operation.
Command :Sb sMM.M#
:Sf sMM.M#
Returns Ok
Sets
the brighter (Gb) or fainter (Gf) magnitude limit for the FIND operation.
Command :Gl# :Gs#
Returns NNN*
Gets
the larger (GI) or smaller (Gs) size limit for the FIND operation.
Command :SI NNN# :Ss
NNN#
Returns Ok
Sets
the larger (GI) or smaller (Gs) size limit for the FIND operation.
Command :GF#
Returns NNN#
Gets
the field radius of the FIELD operation.
Command :SF NNN#
Returns Ok
Sets
the field radius of the FIELD operation.
Command :LF#
Returns Nothing
Starts
a FIND operation.
Command :LN#
Returns Nothing
Finds
the next object in a FIND sequence.
Command :LB#
Returns Nothing
Finds
the previous object in a FIND sequence.
Command :Lf#
Returns (see description)
Performs
a FIELD operation returning a string containing the number of objects in
the field and the
object
that is closest to the center of the field.
Command :LC NNNN# :LM
NNNN# :LS NNNN#
Returns Nothing
Sets
the object to the CNGC (LC), Messier (LM), or Star (LS) specified by the
number. Planets are
‘stars'
901-909.
Command :Ll#
Returns Object Information
Gets
the current object information.
e. Miscellaneous
Command :B+# :B-#
:B0# :B1# :B2# :B3#
Returns Nothing
Increases
(B+) or decreases (B-) reticle brightness, or sets to one of the flashing
modes (B0, B1, B2 or B3).
Command :F+# :F-#
:FQ# :FF# :FS#
Returns Nothing
Starts
focus out (F+), starts focus in (F-), stops focus change (FQ), sets focus
fast (FF) or focus slow (FS)
Command :GM# :GN#
:GO# :GP#
Returns XYZ#
Gets
site name (XYZ). M through P correspond to 1 through 4.
Command :SM XYZ# :SN
XYZ# :SO XYZ# :SP XYZ#
Returns Ok
Sets
site name.
Command :GT#
Returns TT.T#
Gets
the current track 'frequency'.
Command :ST TT.T#
Returns Ok
Sets
the current track 'frequency'.
Command :TM# :TQ#
:T+# :T-#
Returns Nothing
Switch
to manual (TM) or quartz (TM). Increment (T+) or decrement (T-) manual
frequency by one tenth.
Command :Gc#
Returns (12) or (24)
Get 12/24
hour status of clock.
Command :H#
Returns Nothing
Toggle
12/24 hour mode.
Command :P#
Returns "HIGH PRECISION" when
ON "LOW PRECISION" when OFF
Toggles
the High Precision Mode ON or OFF.
Command :U#
Returns Nothing
Toggles
the long format ON or OFF.
When the long format is active, whenever a request to send or receive position
data, the following format is used:
Command :Ls N#
Returns Ok
Sets
the STAR object library type. 0 is the STAR library; 1 is the SAO library,
and 2 is the GCVS library. This
operation
is successful only if the user has a version
of the software that includes the desired library.
f. Keypad Hand Controller Specific
Command :D#
Returns (see description)
Gets
the distance 'bars' string.
Command :$Q (1-5)#
Returns Nothing
Toggles
Smart Drive status.
Command :?#
Command :?+#
Command :?-#
Returns Page of Help Information
Starts
(??) or moves through (?+ or ?-) Help.
Command : G0#
Command : G1#
Command : G2#
Returns Alignment Menu Entry
Used
to implement alignment menu
LX200 Demo Program
The RS-232 interface communicates with your computer
at 9600 Baud Rate, Parity = None, 8 Data Bits, 1 Stop Bit.
For those who are familiar with programming, the
LX200 Command Set is written in ASKII character format and
can be used to write your own programs. The
LX200 Demo Program is written in Quick Basic and is intended to
demonstrate how commands can be sent to the telescope
and information received from the telescope. It is not a
"polished" program and does not incorporate all
of the RS-232 features available. The program is set-up to operate
on serial port 2 (COM2). To operate on serial port
1 (COM1) line 4 should be changad from "COM2 to "COM1.
The program is as follows: Please note that
Meade Instruments does not support these programs, or programs that
you may write in any way. For questions relating
to after-market software programs, refer back to those manufacturers.
LX200 Test Program
Once you have the RS-232 cable constructed you will
want to test the cable. Below is a simple program called "LX200
TEST" that is written in GW Basic programming language
and will work with IBM compatible computers. LX200 TEST
is an effective program to fully check the RS-232
line communications from your personal computer to the LX200,
allowing you to concentrate on de-bugging your RS-232
cable.
To enter the following program, first load BASIC
or GWBASIC (which ever your computer system uses), then type in the
following program. When complete, be sure to save
the program as "LX200TST.BAS."
10 CLS
20 DEFINT A-X
30 OPEN "COM1:9600,N,8,1,CDO,CSO,DSO,RS," FOR
RANDOM AS #1
50 key1$ = INKEY$: IF key1$ = * * THEN GOTO
50
60 REM Key 1 loop
70 IF key1$ = CHR$(119) THEN GOSUB 200:
REM "w" key
80 IF key1$ = CHR$(101) THEN GOSUB 200:
REM "e" key
90 IF key1$ = CHR$(110) THEN GOSUB 200:
REM "n" key
100 IF key1$ = CHR$(115) THEN GOSUB 200:
REM "s" key
105 IF key1$ = "x" THEN END: REM To exit test.
110 GOTO 50 REM return to Key 1 loop
120 END
200 REM.Key 1 direction printouts to COM 1
210 REM west
220 IF key1$ = "w" THEN a$ = "#:Mw#"
: PRINT #1, a$: REM GO west
230 REM east
240 IF key1$ = "e" THEN a$ = "#:Me#"
: PRINT #1, a$: REM GO east
250 REM north
260 IF key1$ = "n" THEN a$ = "#:Mn#"
: PRINT #1, a$: REM GO north
270 REM south:
280 IF key1$ = "s" THEN a$ = "#:Ms#"
: PRINT #1, a$: REM GO south
290 key1$ = INKEY$:
300 IF key1$ = CHR$(32) THEN GOTO 400
ELSE GOTO 200
400 REM This stops motion (by hitting SPACE bar).
410 B$ = "#:Qe#" : PRINT #1, B$
420 B$ = "#:Qw#" : PRINT #1, B$
430 B$ = "#:Qn#" : PRINT #1, B$
440 B$ = "#:Qs#" : PRINT #1, B$
450 RETURN
460 END
To use the above program, connect the completed cable
to your PC serial port and to the LX200 RS-232 Port. Load
BASIC (or GWBASIC), if not already loaded,
and run "LX200TST.BAS - " Nothing will appear on the computer screen.
Press any one of the N, S, E, or W (lower case)
keys on your PC keyboard, this will move the LX200 North, South, East,
or West respectively. Press the space bar on the
PC keyboard to stop. Press X to exit the program. If the LX200 does
not respond to the N, S, E, or W keys, be sure the
CAPSLOCK is OFF. If it still does not work, check the PC serial port
pinouts for your computer to be sure they are wired
correctly to the LX200 6 line connector. With a successful
check-out
of the PC link with the LX200 using "TEST", you
are now ready to write your own software program using the LX200
Command Set or to use the sample program called
"DEMO" that is written in Quick Basic software language.