Testing the Telescope/Serial Port/Cable Using a Terminal Application

Terminal Application for Windows Mobile Devices

Most telescope interface technical support issues are related to bad or incorrectly wired cables. If the cable is not wired correctly, or connected correctly, communications cannot be established with the device and you’ll receive the error message:

I get the error message “<My Telescope Name> not responding. Please check communications port settings, power and connections to the control system.”

This message occurs when TheSky sends a command out the serial port but does not receive a response from the device.

Make sure that the device is has power, is properly initialized and aligned and the cable is securely plugged in at both ends. If you did not purchase your cable from Software Bisque, it may be wired incorrectly or defective. You can verify that the cable, telescope control system and serial port are all functioning independently of TheSky Pocket Edition by using the Windows HyperTerminal application from on your desktop computer to manually send a command to the device. If the HyperTerminal application shows the correct response from the device, then the cables are functioning properly. To do this, from the desktop computer, turn on the telescope control system, connect the telescope interface cable to COM1 and then launch HyperTerminal.

Connecting to Windows HyperTerminal

From HyperTerminal, enter a name for the new connection (for example, My Test Connection) and click OK. Specify the following settings for the serial port: COM1, 9600 Bits Per Second (baud), 8 Data Bits, None for Parity, 1 Stop Bits, and None for Flow Control.
Click File | Properties | Settings tab and then click ASCII Setup. From the ASCII Setup dialog box, mark the option Echo Typed Characters Locally and then click OK.

HyperTerminal is now ready to send a command string to the device attached to the COM port. Sending a command involves typing the appropriate character string (letters) in the HyperTerminal window.

Note: The characters typed from HyperTerminal are sent to the COM port immediately. There is no need to issue a "send" command from HyperTerminal. Also, if you make a mistake typing the character string command, press ENTER several times and start over.

The command string to send to the device depends upon your control system. The table below lists many popular control systems and the appropriate command string to send to the device.

Control System	Command String To Send to Device	Response from Telescope
Astro-Physics GTO Mounts	:GR#	The telescope's current right ascension. Note: You can use this same technique to send other commands to the device.
Encoder-based systems	Q	Current encoder values in the format: +nnnnn nnnnn
NexStar 5 NexStar 8	?	The "#" character.
NexStar 5 NexStar 8	E	Send this command after sending the "?" command. If the telescope is aligned, it returns four hexadecimal values representing the telescope's current coordinates.
NexStar 4 NexStar 8 GPS NexStar 11 GPS NexStar 60 NexStar 80 NexStar 114 Celestron CGE Mounts (all models)	V	The version of the NexStar hand paddle, in hexadecimal format.
	E	The current right ascension and declination of the telescope, in hexadecimal format.
	Kx	X# This command is useful to check the communication.
Sky Commander	<Carriage Return>	This is the same as pressing the Enter key. The telescope's current right ascension and declination as a 16-character ASCII string. For example: "12.345 +67.890" (without the quotes, NULL terminator not shown.)
Ultima 2000	E	If the telescope is aligned, it returns four hexadecimal values representing the telescope's current coordinates.
Autostar	#:GR#	The telescope's current right ascension.
LX200 and LX200-compatible mounts (Gemini, etc.)	:GR#	The telescope's current right ascension. Note: previous versions of the LX200 protocol did not include the first # in the command string. If your telescope uses the LX200 protocol (such as the Vixen SkySensor 2000), omit the first # character. Contact the manufacturer of your telescope for details about its implementation of this protocol.
Takahashi Temma	E	Returns the telescope's current coordinates (ra/dec).

If the device does not respond with the correct command string, one or more of the following is true:

The telescope is not turned on. Make sure that the telescope is powered (Plug the telescope's power supply directly into the appropriate electrical outlet).
The telescope is not properly initialized. Carefully follow the manufacturers instructions for initializing the telescope for software control. Some telescopes must be in "receive" mode before they can communicate with external software.
The telescope interface cable is not plugged in properly or defective.
1. Verify that the cable is wired correctly with an ohm meter.
2. Verify that the cable is plugged in to the correct port (COM or USB-to-Serial Adaptor) on the computer and in the correct port on the telescope.
The selected COM port is not functioning. Try using a mouse, modem, GPS, or other serial device on the selected port.
The telescope hardware (hand paddle or control system) is not functioning properly. Contact the manufacturer of the telescope or control system for details about serial port troubleshooting.

Terminal Application for Windows Mobile Devices

A terminal program can be used to open a serial port and send commands directly to the device connected. This can be useful when troubleshooting problems between Windows Mobile Devices and telescopes.

Click here to download a terminal application (named TTY.exe) for StrongARM processor based Windows Mobile Devices. The application is similar to Windows HyperTerminal, and allows you to test the serial port and cabling for your Windows Mobile Device. Unzip and copy the executable to your device using ActiveSync.

To Setup TTY

Tap File | Settings.
Choose the proper COM PORT (default is COM1) - If you are using Bluetooth check the Bluetooth Device manager!
Set the Baud Rate is 9600.
Set the Parity to None.
Set the Data Bits option to 8.
Set the Stop Bits option to 1.
Set the Flow Control option to RTS/CTS.
Deselect DTR and RTS options.
Select Echo and CR/LF.

Once the correct COM port, baud rate and other settings are set, you can send a commands out the serial port. For example, suppose we are using an LX200 (or compatible) telescope that uses the LX200/Autostar protocol.

From the terminal program issue any LX200 command, such as :GR# (colon, capital G, capital R, pound sign, no spaces, no quotes).

Tap Enter to send the command to the telescope. The telescope, if connected and operating properly, will respond with the current right ascension of the telescope, and this will be displayed on the TTY window.