Originally from ticket #6457.
I would like to connect my Orion XT8g to Starry Nights
From the Orion® SkyQuest™ XTg GoTo Dobsonians user guide (pg. 19)l: http://www.telescope.com/assets/product_files/instructions/29388_11-10.pdf
for #8948 XT8g, #8949 XT10g, #8952 XT12g
Linking with a Computer:
The SkyQuest XTg can be connected to a computer via the supplied computer interface (serial) cable. Many commercially available planetarium software programs can be used to control the SkyQuest XTg. Look for software that is compatible with the Orion SkyQuest XTg Dobsonians, Celestron NexStar5i/8i, or NexStar GPS series. Starry Night Pro is one such astronomy software package. The description below will lead you through the procedure on how to connect and disconnect the SkyQuest XTg to a computer.
1. Align the base as described previously (see “Alignment for GoTo Operation”).
2. Connect the supplied serial cable to the smaller of the two modular jacks (RJ-12) on the bottom end of the hand controller (Figure 22b). Connect the other end of the cable to the serial port of your computer. (If your computer uses USB ports instead of serial ports, you will need a USB-to-serial converter, available at most computer or electronics stores.)
3. In the planetarium software of your choice, choose “Orion SkyQuest GoTo or Celestron NexStar5i/8i or Celestron 8/9/11 GPS (any of these will work) in the driver setup and follow the instructions provided by the program to connect the mount and computer. The SkyQuest XTg will be under the full control of your computer once the connection is successfully established.
First, click here to update your version of Starry Night.
Second, visit http://www.ascom-standards.org to make sure you're updated to the lastest version of Ascom 6.
Third, visit http://www.ascom-standards.org/Downloads/ScopeDrivers.htm to make sure you have the most recent ascom driver package that is compatible with your mount. - In your case you want to download the Celestron driver.
PLease read the Starry Night telescope set up & troubleshooting guide as well: