Celestron C8-S - Manual (Page 58)

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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: