Mosaics put tough requirements on temperature control and housekeeping functions. Thus far, ESO has used PULPO [1] for this purpose. 33 units have been built for 16 instruments, but contemporary mosaics, like ESO's OmegaCAM [2] with 36 CCDs in the focal plane, require a new approach [2,3]. For this reason, ESO has developed a new housekeeping unit, PULPO 2 (see Fig. 1) [4].

Key features of PULPO 2 are:

• Monitoring of 29 PT100 sensors (4 wire system) by default and up to 125 with external multiplexer boards.

• Temperature control of the focal plane with up to 8 independent heaters.

• Monitoring of the vacuum in the cryostat (by means of Balzers or Edwards vacuum gauges).

• Separate alarm outputs for temperature and vacuum.

• Shutter handling with control of the exposure time and measurement of open and close delays.

• Internal logging of numerous system parameters over time (up to 65000 records), thereby making PULPO 2 a valuable trouble shooting and optimizing tool.

• Backward compatibility with PULPO.

The PULPO 2 control software exploits all capabilities of the hardware to implement further functionality for system monitoring and recovery to a safe state in case of failure.

Figure 1. PULPO 2 in the VLT environment.

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