Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 Handbook for the Starlight Xpress SXV-AOLF unit Thank you for purchasing an SXV-AOLF active optics unit. This device should give you much improved guiding accuracy with almost any telescope and mount. Please read the following manual which will explain how the device operates and the best ways in which it can be applied to your optical system.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 The most common method of shifting an image for AO purposes is to use a ‘tip-tilt’ mirror to reflect the beam through a variable angle. This works well, but deviates the optical path through 90 degrees and takes up a considerable back focal distance. Its motion sensitivity is also affected by the distance between the mirror and the CCD.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 oriented so that it is parallel to the AO backplate. This can be seen in the picture at the front of this handbook, as indicated by the orientation of the guide camera socket. The imaging camera is attached to the rear of the OAG, using a suitable adaptor ring. Two types are supplied – one with a ‘T’ thread for the SXV-H9/9C and M25C and one with an M72 thread for the H35 and 36.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 especially useful if you image with narrow band filters, such as H-alpha. A light pollution rejection filter, such as an IDAS P1 or P2 might be best added at the output of the AO unit, where it will improve the guide star contrast, as well as improving your camera images. Note that the recesses are not threaded and so you should be careful that a filter does not fall out and get damaged when dismantling the unit. N.B.
Handbook for the Starlight Xpress AOL unit .
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 Connecting up the AO electronics for STAR2000 guiding: STAR2000 guiding does not require the OAG unit and the camera may be attached directly to the AO. As with off-axis guiding, there is more than one way to connect up the AO for STAR2000 use. Figure 3 shows the most likely way for most users to connect for serial control via the PC.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 General pointers: When the AO unit is first attached to the telescope, it is necessary to arrange the off-axis guide camera, or the STAR2000 camera, so that the East – West AO axis is parallel to the long axis of the guide image. This is easily done by viewing the guider or camera chip through the front of the AO window.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 The SXV-AO can execute an image position correction in a few milliseconds, but the effective correction rate is limited by the brightness of the guide star and the download speed of the guide camera image. For best results with a poor telescope mount, you need to choose as bright a star as possible and use a small guide window. Binning the guide camera image will also help.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 During extreme movement of the displacer, the motors may encounter excessive friction and fail to start. The ‘centre’ command will normally overcome this, as it switches to a much lower speed, high-torque stepping rate after 5 seconds of failure to move. However, in the worst case, you can rotate the motors manually by inserting a small screwdriver through the holes in the front plate.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 Find an interesting object or starfield to image and adjust the ‘scope until a convenient guide star can be seen in the guider field. Ideally, the star should be easily seen in an exposure of only 0.1 seconds and, if necessary, binning may be used to gain sensitivity. Once the guide star is identified, press the ‘Centralise AO’ button and watch the star image – it should cycle through a cross shaped figure and then settle after about 2 seconds.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 socket and the serial port of your PC. The updating procedure also requires the power supply to be connected to the AO. 1) Download the latest version of the updater software from http://www.starlight-xpress.co.uk/SXV-AO.htm 2) Uninstall any previous version of AO Updater using the Add/Remove Programs in the Control Panel. 3) Install AO Updater software by executing the ‘Setup.exe’ file.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 This information is provided for users who wish to write their own control programs.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 Various different functions can be triggered by ‘abnormal’ input pulse patterns. The most useful of these is the ‘centre’ mode, which should be used before beginning any guiding sequence. In this, the inputs are all taken low and then simultaneously released. The AO unit will then rapidly cycle between its limit switches and adjust the window to be centred in the dynamic range and normal to the incoming light.
Handbook for the Starlight Xpress AOL unit Issue 1 1 1 1 0 1 1 0 1 1 0 1 1 0 1 1 1 1 0 1 0 1 0 0 1 0 1 1 0 0 1 0 1 0 0 1 1 0 0 0 0 0 0 0 1 1 1 0 0 21/5/2010 West motor forward South motor forward North motor forward East motor forward West motor back South motor back North motor back East motor back All motors drive back All motors drive forward Enable serial mode and exit set up mode Exit set up mode Copyright Starlight Xpress Ltd.
Handbook for the Starlight Xpress AOL unit Issue 1 21/5/2010 1) The equipment shall only be used for normal purposes described in the standard operating instructions, and within the relevant safety standards of the country where the equipment is used. 2) Repairs under guarantee will be free of charge providing proof of purchase is produced, and that the equipment is returned to the Service Agent at the Purchaser’s expense and risk, and that the equipment proves to be defective.
