Control System

Control of the spectrograph, divided into three control units (the optical system, the cooler and the detector), is carried out using computers in the control building (Figure ).

The optical system is controlled by a local VME board computer, and the cooler is driven by the controller on the Nasmyth platform. The controller of the CCDs (Messia V) is also located on the platform.

Control of the instrument during observation is made possible by communicating with these controllers from the control computer OBCP. The setup and data acquisition, under normal circumstances, are done using several commands (so called abstract commands) from the computer OBS. Some information on the status of the telescope and information on the local environment are also provided by OBS. The CCD data acquired by OBCP using Messia V is transfered to the computer OBC, and stored in the Subaru database automatically.

Initialization, shutdown, and certain special settings of the spectrograph are carried out from OBCP.

Control of the telescope and pre-slit systems (e.g., the image rotators, the calibration sources) is available from the computer TSC, but usually, control during the observation is done from the OBS using abstract commands.

Figure 6: Control system of the telescope and HDS. OBC, TSC, OBCP and OBC are computers in the control building. Users access the computer OBS