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Taking a Geometry Event with Slow Controls

It is not currently possible to use Slow Controls to obtain a geometry event through the HDLC link for several reasons: events stored in the readout board memory are corrupted; only the first time bucket for each channel is set; and the current Slow Controls procedure requires a SAS pulser event (not yet supported). However, one could still presumably use Slow Controls (instead of the Powerbook modem connection to the readout board processor) to give commands to the readout board.

Information on the procedure, edited from email from Jan Chrin, follows:

These jobs do not give meaningful output at present. The EPICS software has been provided, but the readout board Xilinx still needs to be reprogrammed.

Geometric events over the HDLC link were introduced because the ``established method'' of reading FEE addresses and network/node identifiers thru Minidaq (as initiated by a special trigger) led to ``ghosts'' (i.e., non-existent FEE cards would nevertheless show themselves). Slow Controls tests for FEE aliveness by sending a pulse to the FEE SAS and reading out the relevent portion of memory.

Support for geometry events over HDLC was requested by Doug Greiner. The output files were designed for analysis programs and follow a format requested by Mike Lisa/Doug Greiner.


Written: November 11, 1996 by R.Bossingham


Page maintenance:

Roy Bossingham, LBNL
RRBossingham@lbl.gov