General Overview

The setup is using the email notification mechanism available for GRB and Supernovae from the GCN and SNEWS frameworks.
For details on those frameworks see:
http://snews.bnl.gov/alert.html
http://gcn.gsfc.nasa.gov/

The setup has implied those steps:
1) Creation of a pure specific email account named: grbsnalert@ego-gw.it
2) Subscribe to the GCN and SNEWS mailing list using this account.
3) The setup of a dedicated agent which look at the grbsnalert@ego-gw.it mailbox and trigger actions on the received mails.
Such agent has been implemented using the application called "tkbiff"
http://expect.nist.gov/tkbiff/
in a non-GUI configuration so that it can run as a background task on any server
4) The tkbiff customization mechanisms has been then used in order to provide corresponding flags to the Virgo Detector Monitoring System via the file:
/opt/w3/sDoc/runStatus/grbsnAlert.php
Such a file get updated (including GPS time) at the same rate the agent polls grbsnalert mailbox. If the agent do not update anymore the file in case of crash than this will be notified in the Detector Monitoring system as for the other flags generated by Moni processes.
All the tkbiff sutup is made in the file:
/olusers/virgorun/.tkbiff
The initialisation parameters are set in the "init {}"  procedure. From there is possible for example control the polling rate:
set sleep(imap)         60
The trigger actions are defined in the "announce_new_msg {id}" procedure.
Please be careful if you touch this file. It is tcl code and sometime a resulting parser error could be difficult to be clearly identified.
5) The detector Monitoring configuration has been updated by adding the 2 flags: SNAlert.Alert and GRBAlert.Alert under the Section GrbSnAlert.
6) From the Detector Monitoring, by clicking on the specific flag itself, it is possible to visualize the body of the received trigger email providing details of the trigger event
7) resetting the notification flags in the detector monitoring is made by sending a mail to grbsnalert@ego-gw.it with "reset alarms" in the Subject field
8) Test notifications can be generated by sending a mail to grbsnalert@ego-gw.it with "sn" or "grb" in the Subject field

In case of problems with mailbox polling agent

It is possible to monitor the behavior of such agent from its log file:
/virgoLog/GRBSNAlerts/GRBSNAlerts.log
The application can be started from command line (is in the PATH available from /virgo/VCS-7.0/gnu/Linux-i686-SL4/bin/tclbiff.sh) by just typing:
tclbiff.sh &
In case there seems to be problems with this application:

• login on olserver34 as virgorun
• check the application is not running via ps -ef | grep tkbiff
• in case kill it and restart it via tclbiff.sh &

Reducing the frequency of GRB notification

This can be done by making a tuned setup from GCN side by preparing a new setup from:
http://gcn.gsfc.nasa.gov/config_builder.html
in the section:
Modify an existing Site Configuration
By putting Virgo as the "Existing Site Name:"
Otherwise is possible to act at the level of .tkbiff by filtering incoming mail not only on the "From" field but also on Subject or Body field.