Locating guide stars at the Cassegrain focus

1. Move the object to be observed onto the slit using the Cassegrain TV camera.
2. Press the FINDER button on the Grinnell Panel.
3. Press the DIRECT button on the Grinnell Panel.
4. Select the Grinnell menu function GET GUIDE STAR: a horseshoe-shaped acquisition field will appear on the Grinnell TV monitor.
5. Choose a star within the permitted area which is visible without integration (otherwise it will be too faint for the autoguider).
6. Move the Grinnell cursor to the desired guide star and press ACCEPT on the joystick.
7. If you have been operating the autoguider in Telescope Mode, or just to be sure, switch to Probe Mode by typing at the User Interface:

   AC/PR

8. Acquire the guide star by going through the field - acquire - guide - loop/enable sequence described below in section .