HVS 1/99

Here is a brief rundown on how the BPM SAMPLER works, according to information
I got from Linda and Janice in June 1998.

This is the control system thingy which gathers data for HSTB of toroids,
GADC readouts, and stuff like that which falls under BPM acquisition.

There is a "control file", which specifies specific measurement acquisitions
to be made. Each line specificies an acquisition. This control file is 
SLCBS_CTRL:BPM_SAMPLER.CTRL. A line looks like;

START "PEP2INJF TORO"/NOLOG/NOBPM/BPMD=26/PULSES=1/DELAY=360/END_TIME=6:57/GADC=SLCBS_LISTS:PEP2INJF.DAT/FMICR=LI10/LMICR=PI11

For this acquisition, a list of toroids are read out. One pulse. BPMD number 26 is used, 
and that is where all of the beamcode, incl/excm masks, bunch number, display group, etc.  
come from. The list of toroids to readout is as specified in the file called
SLCBS_LISTS:PEP2INJF.DAT, which looks something like;

'TORO','LI10',4043
'TORO','LI13',4300
'TORO','LI28',5877
'TORO','PI11',6404

So manipulation of these files is the way in which changes to what gets sampled
would be done. Privilege (SLCSHR) is required to change these files, but the
SLCSHR privilege is granted to the EOIC_DESK account, so it can be done there.

Of course once the file changes are implemented, the BPM_SAMPL process must
be restarted with WARMSLCX.