Troubleshooting the SGT Connection

If you are having trouble establishing a link between TheSky and the SGT (software-guided telescope) system, you should follow this troubleshooting guide for possible solutions. While it is common to suspect the decoder (BBox, NGC-MAX or look-alike) or cable, it is rare for either to be the cause.

CONNECTION — Ensure that the RJ11-to-DB9 adapter (the part on the cable which connects to your computer’s serial port) is the correct one. Two such adapters may have been included with this cable—one for the LX200-series, the other for the BBox and compatible devices. If these adapters are not labeled, please contact JMI for help in identifying the correct adapter. If you are unsure which is the correct adapter, you may try both. The serial cable must be attached to a 9- or 25-pin D-subminiature male connector on the personal computer. Other connectors on the computer (D-subminiature female, RJ11 modem jack, etc.) cannot be used with the SGT system!

SETUP — Verify that the interface COM Port setting under TheSky is correct. Each of your serial ports has a different COM port assignment, most commonly between 1 and 4. If possible, test another serial device on this same COM port to confirm that the port is working properly. If you believe the port to be non-functioning, check the IRQ and base address settings. Here’s how:

Windows 3.1x or Windows NT 3.5x
1. From Windows’ Program Manager, select the Main program group.
2. Run Control Panel.
3. Choose Ports.
4. Click on the COM port you have the decoder attached to.
5. Select Settings, then Advanced.

Windows 95 or Windows NT 4.0
1. Choose Start / Settings / Control Panel.
2. Open (double-click) the Ports icon.
3. Click on the Port you have the decoder attached to.
4. Select Settings, then Advanced.

Make a note of the current Base I/O Port Address and Interrupt Request Line settings.
If necessary, correct these values. If you don’t know what they should be, consult your computer manual or a computer technician. A common problem is two COM ports conflicting with each other.

TEST — Check the decoder independently of TheSky. Here’s how:

Windows 3.1x or Windows NT 3.5x
1. From Windows’ Program Manager, select the Accessories program group.
2. Run Terminal.
3. From the Settings menu, choose Communications.
4. Set Baud Rate to 9600, Data Bits to 8, Stop Bits to 1, Parity to None, and Connector to the COM port that the decoder is attached to.
5. Choose OK.
6. From the Settings menu, choose Terminal Preferences.
7. Set Local Echo active, and CR->CR/LF to Inbound and Outbound.
8. Choose OK. Skip to step 9 below.

Windows 95 or Windows NT 4.0
1. Choose Start / Programs / Accessories / HyperTerminal.
2. Run HyperTerminal (Hyperterm.exe).
3. If prompted for a New Connection Name, you may choose Cancel.
4. From the File menu, choose Properties.
5. Set the Connect Using parameter to the COM port that the decoder is attached to.
6 Choose Configure, then set Bits Per Second to 9600, Data Bits to 8, Parity to None, Stop Bits to 1, and Flow Control to None.
7. Choose OK from the COM Properties window.
8. Choose OK from the New Connection Properties window.
9. Turn the decoder on. You should see V2.00 or similar on your screen.
10. Type an uppercase letter P. You should see P001 or similar on your screen. If instead you see just the letter P, then you may have a problem with the computer, cable, or decoder.

If you are still having problems with your SGT connection after following these steps, please feel free to contact our technical support staff for further assistance. You may be asked to provide information obtained from one or more of the above steps. 

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