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
Resetting the DEIMOS rotator requires pushing one or two buttons
on the instrument to restore remote control.
- 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.
- 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
- Once you have removed the panel, push the green reset
button on the rotator controller (see figure
- 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,
- Be careful: after you have pushed the reset button,
DEIMOS may rotate! It can take a minute or two for that to
Figure 1. Panel to be removed for resetting rotator.
Figure 2. Location of rotator reset buttons.