Telescope Interface Options

The Options... command in the Telescope menu lets you access several options of the telescope interface (SHIFT+F12 is a shortcut for this command). The options dialogue box can also be accessed with the Options... button on the telescope hand controller (see the telescope hand controller section).

Copies of screen shots below provide the main items of information about each of the telescope interface options.

Interface tab

This tab lets you select the telescope connected to your computer. At this time, 6 types of telescopes are provided for (native LX200, SkySensor 2000 PC, AudeCom, Gemini Pulsar, Astro-Physics GTO and ASCOM standard).

Note that when the telescope is controlled through a serial port, the Reset button lets you interrupt communication with the telescope and then reset the dialogue between the PC and the telescope.

For telescopes controlled with the ASCOM standard, you must previously have installed a driver which is not provided with C2A. Go to, download the "ASCOM Platform 4.1" (which is the version available at the end of 2006) or a more recent version, and install it on your computer. Once the drivers are installed, you can choose the telescope you wish to control by clicking on the Telescope driver button.

Commands Tab

Reverse Alpha commands – When this option is checked the movements on the Alpha axis issued by the hand controller are reversed.

Reverse Delta commands – When this option is checked the movements on the Delta axis issued by the hand controller are reversed.

Allow telescope movements during tracking – This option allows you to to send movements to both axes even while the Alpha axis is tracking. Note that this option is really useful only for the  AudeCom controller in native mode, which is the only supported telescope for which you can choose whether or not to start tracking.

Stop telescope movements when starting to track - This option is useful only for the AudeCom controller in native mode.

Meridian Flip – This area lets you indicate if you want to allow an automatic meridian flip for a telescope on a Geramn equatorial mount. It is advisable to use it only for the AudeCom controller with a German equatorial mount.


Labels Tab

This tab lets you specify the labels that appear on the hand controller near the four command buttons


Display Tab

Display action messages on the interface – If this option is checked, messages related to the telescope are displayed in the message area of the hand controller.

Display hour angles rather than right ascension – If it is checked, this option allows you to indicate whether you wish to display the telescope pointing direction in hour angles or right ascension on the hand controller.

Hour angle in the range -12 to +12 hours – When it is checked, this option allows you to specify whether hour angles should be displayed in the range -12 to +12 instead of 0 to 24 hours on the hand controller.


System Tab

In the case of a telescope controlled natively through the serial port (see above how to choose this option), position demands from and commands sent to the telescope are generated by a software Programmable Logic Controller integrated with C2A. If the position demands are too frequent for the speed of the machine running C2A, the PLC may become saturated, and this will produce an error message. You must then change the two values shown in this tab to change the performance of the PLC to avoid the error message. It is advisable to experiment with decreasing the value in the Action queue (this value specifies the cycle time of the PLC) and increasing the value of Position request (this value specifies how often the telescope encoders are interrogated).


Misc Tab

Automatic target tracking – This option lets you indicate that when the current telescope position leaves the field in the main screen, the field is re-displayed so that the position of the telescope appears in the centre of the screen.

Display the hand controller when C2A is launched – This option indicates that the hand controller should be displayed when C2A is launched.

Hand controller always on top – This option indicates that the hand controller should always be displayed on top of the main C2A window. This can be useful when resolution does not allow all windows to be displayed without overlap.

Automatically connect to telescope – This option indicates that the connection with the telescope should be made as soon as the hand controller is displayed.

Types of reference points – C2A lets you display specific views in which important stars are highlighted (see the section How to use reference stars to calibrate a telescope). You can select two types of reference stars: calibration stars over the whole sky, or stars for polar alignment. For the second type of stars, you can specify the symmetries to apply to the field.

Debug mode – In this mode, details about the command messages sent to the telescope are displayed in the message area of the hand controller.

Debug file – You can systematically send all detailed message about commands sent to the telescope to a file so that they can be analysed in detail.


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