Background

When a Keck 2 E-stop button is pressed or a power glitch occurs, the event can trip the DEIMOS rotator control, thus disabling the rotator. You can check whether the rotation is disabled by checking ther state of the ESTOP from DCS indicator on the DEIMOS dashboard's Rotation subpanel; if the button is red, then the ESTOP must be reset following the procedure below. Note: if both the ESTOP and PANIC indicators are on, that probably indicates that you need to power cycle roto.

Procedure

Resetting the DEIMOS rotator requires pushing one or two buttons on the instrument to restore remote control.
  1. Go to the side of the instrument with the hand paddle. From the back of the instrument, facing the telescope, this is the right side.
  2. Move the hand paddle to the side, and remove Panel C (see figure 1 below) to gain access to the buttons. No screws need to be undone; the panel just rests on a couple of pegs. The panel has a handle on it and just lifts off.
  3. Once you have removed the panel, push the green reset button on the rotator controller (see figure 2 below).
  4. Ask the support astronomer to check whether the rotator is now functional. If not, then you might have to push the reset button on the rotator computer as well (shown in figure 2). Do not do this unless requested, though!
  5. Be careful: after you have pushed the reset button, DEIMOS may rotate! It can take a minute or two for that to happen.
  6. Note: If you reboot the rotator computer you will likely need to restart the deirot processes. You can do this in either of two ways:

Figure 1. Panel to be removed for resetting rotator.

Image showing panel to be removed for resetting rotator

Figure 2. Location of rotator reset buttons.

Image showing location of rotator reset buttons.