The NSCL production readout software. -- Scaler data buffers

Scaler data buffers

Scaler data buffers

Scaler data buffers contain data from run time counter modules. Normally they are used to provide status information like trigger rates, and integrated beam current. The scaler data are read incrementally (read and cleared), so they are in very little danger of overflowing, as long as the readout interval is not unreasonably long.

The format of the scaler body is:

Format of scaler buffer body

Buffer word offset	words	contents
16	2	Interval end time in seconds
18	3	Unused words
21	2	Interval start time in seconds
23	3	Unused words
25	varies	longword scaler values

Note

The entity count field of the header is set to the number of scalers that were read out.
Each scaler is a longword in the natural byte order of the creating system.
Of course the Start time of a subsequent buffer should be the end time of the previous one, and the first scaler buffer will have a start time of 0.
Scaler buffers are produced just before run halting state transitions (transitions to paused and inactive).

Report documentation errors to Ron Fox (fox@nscl.msu.edu)or NSCL's Bugzilla page

Scaler data buffers