This section details the requirements for the monitoring of pedestal averages and widths.
Requirement:
The On-Line SVT Monitoring system must monitor the pedestal averages and width of all SVT equivalent pixels.
Justification:
The Pedestals are an essential part of the SVT calibration chain as they directly affect the quality of data taken under zero suppression mode. Wrongly set pedestals could cause the loss of valuable data or the readout of unnessary segments of the detector thereby increasing the load on the DAQ taping process. In addition, the width of the pedestals is an excellent indicator of the energy resolution of the detector elements, it also provides indications of noisy channels and or dead channels.
Requirement:
The On-Line SVT Monitoring system must provide displays to examine the pedestal averages and widths as well as the number of entries for each channel. There should be multiple ways to view the data
Justification:
It is necessary to examine the value of the averages and the widths. This examination may proceed channel by channel or may require to compare a large range of channels. Alternatively, a graphical display allows a quick examination of the values to check trends across the detector or to verify that the values are within tolerance.
Requirement:
The On-Line SVT Monitoring system can be used to set tolerances on the minimal and maximal values of the pedestal averages, widths, and number of entries. Excursion beyond these tolerance limits will be the basis for the generation of alarms.
Requirement:
A somewhat ``fine'' granularity is available for the specification of tolerances. i.e. it is possible to define tolerance for small groups of channels on a wafer basis, and anode basis.
Justification:
Different parts of the detector might behave differently even under optimal conditions.
Requirement:
Alarms (Yellow) are generated when one or more channels become out of tolerance.
Justification:
A non-severe situation that must be reported to the operator.
Requirement:
Alarms (Red) are generated when large groups of channels become out of tolerance.
Justification:
A severe situation possibly indication serious a mal-function of some components of the SVT hardware must be reported to the operator.
Requirement:
The pedestal monitoring process checking that averages and widths are within prescribed tolerances is run every time a new pedestal calibration becomes available.
Justification:
This insures timely examination of the calibration.
Requirement:
The pedestal monitoring process checking that averages and widths are within prescribed tolerances can be run at any time by the monitor operator.
Justification:
The operator can thus set new or different
tolerances and verify immediately whether the current calibration
satisfies those tolerances.