Appendix d - rs-232 connection – Celestron Advanced Series C5-S User Manual
Page 61

61
Appendix D - RS-232 Connection
You can control your telescope with a computer via the RS-232 port on the computerized hand control and using an 
optional RS-232 cable (#93920). Once connected, the telescope can be controlled using popular astronomy software 
programs. 
Communication Protocol:
The Advanced GT communicates at 9600 bits/sec, No parity and a stop bit. All angles are communicated with 16 bit 
angle and communicated using ASCII hexadecimal. 
Description
PC Command ASCII
Hand Control Response
Notes
Echo
Kx
X#
Useful to check communication
Goto Azm-Alt
B12AB, 4000
#
10 characters sent. B=Command, 
12AB=Azm, comma, 4000=Alt. If 
command conflicts with slew limits, 
there will be no action. 
Goto Ra-Dec
R34AB, 12CE
#
Scope must be aligned. If 
command conflicts with slew limits, 
there will be no action. 
Get Azm-Alt
Z
12AB, 4000#
10 characters returned, 
12AB=Azm, comma, 4000=Alt, # 
Get RA-Dec
E
34AB, 12CE#
Scope must be aligned
Cancel Goto
M
#
Is Goto in Progress
L
0# or 1#
0=No, 1=Yes; "0" is ASCII 
character zero 
Is Alignment Complete
J
0# or 1#
0=No, 1=Yes
Commands below 
available on version 1.6 
or later 
HC version
V
2
2
Two bytes representing V2.2
Stop/Start Tracking
Tx 
x = 0 (Tracking off) 
x = 1 (Alt-Az on) 
x = 2 (EQ-N) 
x = 3 (EQ-S) 
#
Alt-Az tracking requires alignment
32-bit goto RA-Dec
r34AB0500,12CE0500
#
32-bit get RA-Dec
e
34AB0500,12CE0500#
The last two characters will always 
be zero. 
Commands below 
available on version 2.2 
or later 
32-bit goto Azm-Alt
b34AB0500,12CE0500
#
32-bit get
Azm-Alt
z
34AB0500,12CE0500#
The last two characters will always 
be zero. 
The cable required to interface to the telescope 
has an RS-232 male plug at one end and a 4-4 
telephone jack at the other end. The wiring is 
as follows: 
