An External Trigger Alert System for the LIGO Control Rooms

Document #:

LIGO-T1500197-v2

Document type:

T - Technical notes

Abstract:

This document describes the external trigger alert system designed to run in the LIGO observatories' control rooms.

This is a python code that queries GraceDB for recent external trigger events and populates EPICS channels within the control room system with event information (GraceDB ID, time, type, source). The code also disables hardware injections for a set period of time upon receipt of an alert and provides a heart beat after each successful query for process monitoring purposes. An accompanying MEDM screen displays all this information for users and features a button that will open the GraceDB event web page of the latest external trigger event.

Files in Document:

• exttrig_alerts.pdf (file is not accessible)

Other Files:

• Fig. 1 (exttrig_alert_medm.png, file is not accessible)
• Fig. 2 (exttrig_alert_medm_warning.png, file is not accessible)
• bibtex file (exttrig_alerts.bib, file is not accessible)
• tex file (exttrig_alerts.tex, file is not accessible)

Topics:

• Astrophysics / Multi-messenger

Authors:

• Andrew Williamson
• Alexander Urban
• Duncan Macleod