omicron_virgo.md

@@ -44,6 +44,20 @@ printchannels /virgoData/ffl/raw.ffl $(( `tconvert now` - 1000 )) | awk '$2>100
 ```
 This command prints all the channels with a sampling rate larger than 100 Hz and with the correct format for Omicron configuration files. Of course, you can filter these channels with extra bash command (e.g. `grep`).
 
+## Omicron triggers
+
+Omicron triggers are produced continuously with dedicated online processes (see the [https://vpm.virgo.infn.it:40000/main.html?subsystem=DetChar](detchar processes in vpm)). Hundreds of channels are processed and triggers are saved to disk. These triggers can be used by anybody for glitch investigations.
+
+Triggers are saved in ROOT files following the `GWOLLUM` convention for triggers. Trigger files can be found in:
+```
+/data/omicron/V1
+```
+For most cases, the trigger file location and/or format is irrelevant as Omicron triggers can be accessed automatically by [home#programs](omicron applications).
+
+Following a reorganization of the storage area at Cascina, the Omicron trigger file location is currently (O3) only accessible from online machines: `detchar1` or the `ctrl` machines but not the `farmn` machines.
+
+If you get the error "No trigger files", look at the [faq](FAQ). 
+
 
 ## Other applications