Ports and Connectors on CGEM Scopes
Click
here for a diagram
by Larry McNish depicting NexStar cable/port connections.
- RS-232 or USB Port - located on the bottom of the hand control.
Hand controls manufactured prior to 2014 are RS-232; those manufactured
starting in 2014 are USB. The RS-232 port is presented as an RJ-22
jack (looks like a small telephone jack). The USB port is a
mini-USB as found on devices like digital cameras, not the more common
micro-USB found on smartphones. The
primary usage of this port is for controlling your scope with the wide
variety of astronomy software available for PCs, Macs and PDAs. A
secondary usage is for updating the firmware in the hand control or
mount's motor control
- details are found here.
Details about the required connector cables are found in
this section of the website.
- HAND CONTROL Port - located on the control panel on the right
ascension motor housing. This is the port for connecting the hand
control to the mount. The hand control may also be connected to the
AUX port. The connector is a 6 conductor RJ-12.
The signaling is TTL and so a serial port on a PC should not be
connected to this port.
- AUX Port- located on the control panel on the right ascension
motor housing. This port is designated for "smart accessories", for example, the optional CN-16 GPS module - Celestron part
number 93963. Also, as noted above, the hand control can be
connected here as well. The connector is a 6
conductor RJ-12. The signaling is TTL and so a serial port on a PC
should not be connected to this port.
- AUTO GUIDE Port - located on the control panel on the right ascension
motor housing. This port is designed for connecting a standard
autoguider - generally based on a CCD camera. The connector for this
port is an RJ-12 and the pin designations are found
here.
Also, you can build or buy a manual hand control that allows manual
guiding or fine movement control and connect it to this port - details are
found
here.
- POWER CORD Connector - located on the control panel on the
right ascension motor housing. This is the connector for the power source
driving the scope - details on this connector are found
here.
Also, it should be noted that Celestron offers an Auxiliary Port
Accessory Kit (part number 93965) that can be connected to the HAND CONTROL
port and then provides the following ports:
- AUX 1 and AUX 2 Ports. Two AUX ports with the same
function and description noted for the AUX port above. Most likely
you will have no reason to purchase the aux port kit for these
additional ports.
- PC Port. This port can be used with two software packages
from Celestron. The first is for upgrading the motor control
firmware, though with a functioning hand control, motor control
firmware can be updated via the RS-232 port on the bottom of the hand
control as well. The second is for a PC-based virtual hand control
called NexRemote - details are found
here. NexRemote can also be used by connecting
the PC via the RS-232 port on the hand control - the PC port just has the
advantage of not requiring the real hand control to even be connected.
The connector for this port is an 8 conductor RJ-45. The signaling
is standard RS-232 levels. When using NexRemote with the PC port,
you need a "programming cable", not the standard RS-232 cable used to
connect to the port on the bottom of the hand control. Click
here for details on the cable used to connect this port to a PC.
And finally, Ken Hutchinson has put together a document detailing how to
build an adapter that connects to the HAND CONTROL or AUX port and then provides a
PC Port that works as described above. For more on this adapter, click
here.
|
