Calibration Access and Data Handbook

Procedure

The routine simple makes a transparent read to return the following data:

1. The $eduThreshold$, which is the value in ADU's of the threshold currently applied to events. Because there may be 2 different ADU threshold (for inner and outer CCDs respectively) per mode, then each extension will have two attributes describing this
2. The patterns data which are a 3-d array comprising the index of pattern identifying number, and a 5$\times$5 array describing the significance of each pixel within the patterm

Note that the outer CCDs should remain in a Full Window mode of readout, so that except for any change in their EDUThreshold values with mode, then only the pattern IDs of the central CCD are expected to change with mode (and currently only for the FAST mode). For completness and possible future developnent there is a separate extension per MODE for the patterns library of this central CCD.