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How to Upgrade Hand Control Firmware - NexStar+

To update the hand control firmware, you will need the Celestron Firmware Manager (referred to as CFM for the rest of this document) from Celestron's web site:
Click the CFM folder and download the "zip" file and follow the directions below.

Click the Drivers and Software category link, then Show More towards the bottom of the page and search for the Celestron Firmware Manager.  Download the "zip" file and follow the directions below.

CFM uses Java (download the latest from to work on Windows, Mac OS and Linux.

Updating your scope also requires the standard Hand Control RS-232 Port Cable that plugs into the bottom of the hand control.  For details on the cable and sources to purchase one, read this.  You must connect this cable between the serial port on your computer and the port on the bottom of the hand control.  If your PC does not have a serial port, you will need a USB-to-serial adapter available at most computer stores.  See PC Control on this web site for more information and options regarding computers without a serial port.

After downloading CFM, you must then "unzip" or "extract" it to a folder on your computer.  Don't lose track of the location of this folder as you will need to navigate to it to start CFM later.

Here is a quick overview of the upgrade process:

  • Connect the serial port of your PC to the RS-232 port on the bottom of the hand control.
  • Open the folder where you unzipped and double-click CFM icon.  There might be two CFM icons - only one will open the orange CFM program window.
  • CFM will automatically scan the computer's serial ports to locate the connected hand control.  After locating it, the top section of CFM will state it has identified your telescope.
  • CFM will also automatically download all packages (firmware) in the center section.  Note that this can occur without being connected to the hand control - for example, if your scope is out in an observatory without Internet access, you could start CFM while your laptop is connected to the Internet and later take the laptop out to the observatory.
  • Once the download is complete, click the Update button in the bottom section to load the firmware into the hand control.

Additional Notes - Hand Control Menu Items

  • Use the Languages menu item to select which language set to load into the hand control - European or Asian (English is loaded in both cases).  Be sure to set the option in the bottom section of the window to Always do what I selected this time.
  • Use Mount Type if the hand control comes up with the wrong firmware, for example, one of the equatorial models (Advanced GT, CGEM, etc.) when you have an alt-az model (CPC, NexStar SE, NexStar SLT, etc.). After choosing the correct telescope type (Alt Az or Equatorial), be sure to set the option in the bottom section of the window to Always do what I selected this time.

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