Overview
The EPICS Alarm Handler (ALH), developed at Los Alamos and Argonne, is an interactive graphical application that displays and monitors EPICS process variable alarm states. ALH communicates with the EPICS database using channel access function calls and displays a hierarchical, navigable tree of PVs and their alarm states, as specified by configuration files. ALH logs alarms and operator actions to CMLOG, and to its own log files. For a detailed description click [here.|http://www.slac.stanford.edu/grp/cd/soft/share/slaconly/alh/index.html#alhslac]
The Alarm Handler Browser run on the LCLS server as a background task connecting to a groups of PVs as listed above. This process is started from the laci account. The standalone process logs alarm messages to CMLOG and to the ALH Alarm and OpMod log files listed below in Table 1-3. This process is run without X displays, using Xvfb, a virtual framebuffer X server for X11.
Manuals
Configuration
References
Table 1-1 |
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Description |
CVS Repository |
CVS Reference Directory |
Source |
/afs/slac/g/lcls/epics/extensions/src/alh |
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---|---|---|
Daemon Script |
/afs/slac/g/lcls/tools/alh/script |
|
Browser Script |
/afs/slac/g/lcls/tools/script |
|
Configuration |
/afs/slac/g/lcls/tools/alh/config |
|
|
|
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Table 1-2 |
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Description |
Directory |
|
Logs |
/nfs/slac/g/lcls/tools/alh/log |
Note: Log files are accessible from the host lcls-dev only. Log files are not stored in CVS.
Alarm Handler Processes
There are 2 uses of the alarm handler for LCLS
1. The Alarm Handler Daemon Process: a single instance of this runs in without a visible browser. Its sole function is to log alarms to cmlog.
2. The Alarm Handler Browser: displays the alarm tree for operators and whoever else is interested. Can be started in 2 modes:
Start Alarm Handler Browser in Spy Mode
Start Alarm Handler Browser in Sup Mode
Restart Alarm Handler Daemon process
+Stop Alarm Handler Daemon process +
+Start Alarm Handler Daemon process +
View Status of Alarm Handler
Start Archiver Watchdog
The cron job tscron.watchdog is use to monitor the status of the ALH Process running on the host lcls-dev. The cron job generates the log file /tmp/watchdog.log. This log file provides status information for diagnostic purposes only. The cron job also read and write the files listed in Table 1-3 below.
To restart a cron job:
Start Alarm Handler Heart Beat
Table 1-3 |
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Directory: /home/tools/alh/dev/log |
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Host Access: lcls-dev |
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Filename |
Description |
Access |
Alarms |
Alarm Log |
read-only |
OpMods |
Operation mode |
read-only |
System Administration