16
ASSEMBLY INSTRUCTIONS
Understanding Cabling Differences in Non-AE and AE Mounts
Offering the option of Absolute Encoders to the 1100GTO mount presented some design challenges. Apart from creating
a robust and high precision system, it was important to find an elegant and aesthetic solution that would minimize cable
clutter and also take advantage of the mount’s internal cabling feature. A brief summation of the cabling differences
between the standard 1100GTO mount and the Absolute Encoder version of the 1100GTO mount (1100GTO-AE and
1100GTO-AEL) follows.
1100GTO
The 1100GTO mount (standard version) uses our traditional Y-cable design of the servo motor cable to connect the R.A.
and Dec. motors to the GTOCP4 control box. This Y-cable (S1100GYCR) is proprietary to the 1100 mount and cannot be
used with any other mount. Its longer Dec. branch is run internally through the R.A. axis and then exits a cable port on the
front of the Dec. axis. It then connects to the motor box. The cable port has a slotted cover that will slide shut and protect
against dust and insects. This cable is user installed.
Additionally, please note that there is a slotted access port
cover on the rear plate of the R.A. polar axis though which
the lower end of the Dec. cable can pass.
The R.A. servo cable branch will connect to the R.A. motor
box externally.
Finally, the connector which joins the two servo cable
branches will be attached to the GTOCP4 box at the
connector marked “motors”.
1100GTO-AE / AEL
The 1100GTO-AE and 1100GTO-AEL Absolute Encoder versions of the mount utilize
a more complex cabling system that communicates encoder Readhead information
as well as the motor servo information. We call this cable system the X-cable system.
The Dec. AE Readhead connects to the motor
box via a 9-pin DE-9 connector. The encoder
information, along with the Dec. motor servo
information, is communicated via a single cable
that connects and looks like the cable described in
the section above. This cable is pre-installed at the
factory.
From the round connector on the motor box the
servo cable runs through the cable port with the
slotted cover and then internally through the R.A.
axis, exiting through the slotted cable port on the rear plate of the R.A. polar axis.
Unlike the Y-cable described above, this cable screws into to a junction box on the
underside of the polar axis.
The junction box sorts the Absolute Encoder and servo motor information/wiring
of both axes. It has three cables hard wired into it. One cable on the east side
(northern hemisphere) goes to the R.A. motor box for communication to both
the AE Readhead and the R.A. motor
externally. The other cable on the east
side connects to the GTOCP4 connector
marked “encoder”. The final cable exiting
the junction box from the west side
goes to the GTOCP4 connector marked
“motors”.
AE Readhead
Cable
Servo Motor
Cable
R.A. Motor Cable
Dec.Motor Cable
Junction
Box
Servo Motor
Cable
AE Readhead
Cable