DESCRIPTION

STEMP Sets the CCD cooling temperature for the surrent CCD controller and head. It will take a much longer time to cool down than to heat up. Note that the CCD should not be cooled unless there is a flow of Dry Nitrogen gas through the Peltier enclosure. Permanent damage may result. The Nitrogen monitoring system has been introduced to ensure a constant flow of dry gas.

CALLING PARAMETERS

t - Temperature in integer degrees Centigrade -50 <= t <= 20

INITIAL/DEFAULT VALUE

Dependent on CCD controller firmware - currently 20 Degrees C. With the V2.X CCD firmware, the default in -35 Degrees >C, and the chip is not cooled without air flow.

RETURN VALUES

None

RESTRICTIONS

The CCD should NOT be cooled unless there is a flow of Dry Nitrogen gas through the Peltier enclosure. PERMANENT DAMAGE MAY RESULT.

.FLOW ( - )

DESCRIPTION

.FLOW is a high level engineering diagnostic routine which interrogates the current CCD controller to find out the state of the Nitrogen Flushing system. The command displays the current flow rate and interlock threshold parameters, whether the interlock is enabled and if it is operating. There is a flow sensor on the exhaust port of the Peltier CCD enclosure, and if there is not enough flow, the CCD is not allowed to be cooled due to the danger of ice crystals forming on the CCD face and damaging it. The interlock can be overidden from the VME system.

The Autoguider will, in later versions, monitor the CCD temperature and the Nitrogen Flow rate occasionally in a background task, and report problems over the Utility network.

CALLING PARAMETERS

None.

INITIAL/DEFAULT VALUE

None

RETURN VALUES

None

RESTRICTIONS

The background flow monitoring task is not implemented in this release.

EXAMPLE

AUTOGUIDER> .FLOW

flow rate threshold = 5

current flow rate = 7084

flow rate ABOVE threshold

Interlock disabled

CCD temp: -318

AUTOGUIDER>