NexStar Resource Site

line.gif (861 bytes)
Pop-Up Info Window
(close when finished)
line.gif (861 bytes)

Ports and Connectors on NexStar GPS 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 in the hand control recess in the fork arm.  The primary usage of this port is for connecting the hand control, however, this port is actually the same as the two AUX ports on the base of the scope, and so, the hand control can be connected to those ports 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.
  • AUX 1 and AUX 2 Ports- located on the top of the base of the scope.  These ports are designated for "smart accessories", however, Celestron has yet to release any applicable to the GPS scopes.  As noted above, the hand control can be connected here rather than in the fork arm.  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 top of the base of the scope.  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.
  • PC Port - located on the top of the base of the scope.  This port can be used with two software packages from Celestron.  The first is for upgrading the motor control firmware, though with hand control version 4.13 or higher, 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.  All other software on the market either communicates via the RS-232 Port discussed above or communicates with NexRemote which in turn communicates with the scope via this port.  The connector 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.
  • +12V OUTPUT Connector - located on the top of the base of the scope.  This connector feeds 12VDC power through the scope to provide power for small accessories.  The connector is just like the power cord connector on the bottom of the base - a barrel connector with outside diameter of 5.5mm and inside diameter of 2.1mm.  Positive voltage is on the inside conductor, negative on the outside.  There is no official power rating given by Celestron, but the general consensus is no more than 750ma - that means NO heater strips.  Small accessories like focuser motors or cameras should be OK.  For more details, read here.
  • POWER CORD Connector - located on the lower part of the base, right above the tripod head.  This is the connector for the power source driving the scope - details on this connector are found here.

line.gif (861 bytes)

line.gif (861 bytes)
Copyright
Michael Swanson
 
  Contact the webmaster:
swanson.michael@usa.net