Dave Barker. WP5269

I have put together a quick EPICS alarm handler for Gamma Ray Bursts and Supernovae (GRB/SN) which runs on the operator alarm machine. It is called grbsn.alhConfig (in svn under cds/h1/alarmfiles).

The GRB alert system (which runs on h1fescript0) polls the GraceDB database every 10 seconds looking for External events (Gamma Ray Bursts and Supernovae). If an event is detected, its information is written to EPICS records which are hosted on the FE model h1calcs.

To put together a quick alarm system for ER7, I am using the alarm fields of the H1:CAL-INJ_EXTTRIG_ALERT_TIME record which records the GPS time of the trigger. By setting the HIGH alarm field to the current GPS time plus one second, when the next event is recorded this PV goes into the MAJOR alarm state.

The grbsn.alhConfig file provides the operator with two buttons:

[G] button opens the guidance text. It refers to the alog entry  https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=19037

[P] button runs a script which resets the alarm level to the current event, turning off the current alarm

When a GRB/SN alarm is raised the operator should:

1. acknowledge the alarm to stop it beeping/flashing

2. press the [P] button to turn off the current alarm and prime the system for the next event

3. read the guidance to see if any further action is needed

Information on the current event can be obtained by running the script grb_latest_event_info.py. This gives you the event time as local time, so you can easily determine when the one hour stand-down time will expire.