Online Monitoring at Hermes

Paper: 236
Session: B (poster)
Presenter: Shutov, Vitaly, DESY, Hamburg
Keywords: monitoring systems, data bases, data interchange, GUI's, world-wide collaboration

Online Monitoring at Hermes
Ralf Kaiser

TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C. V6T 2A3
and Simon Fraser University, Vancouver, Canada

for the Hermes Collaboration

The online monitoring of a large particle physics experiment like Hermes
has to fullfill a series of requirements. The status of the experiment has
to be known in great detail at all times. These status data have to be recorded
in a format that can be combined easily with the data taken by the experiment
for later offline analysis. At the same time they have to be presented to the
shift crew in a reliable way that allows for quick and efficient problem
identification and that points at possible causes and solutions.
To this end it is desirable to incorporate expert knowledge about the
different components of the experiment into the monitoring software.
It is equally desirable to make the online monitoring information readily
available to the component experts in their home institutes.

The approach the Hermes collaboration has taken to provide a coherent
online monitoring solution is based on three components: Adamo,
Dad and PinK.
Like the physics data structures the online monitoring data structures
are also based on the Adamo entity relationship model.
The Adamo model is complemented by the client-server based
Distributed Adamo Database (Dad),
which turns a collection of Adamo files into a cross platform accessible
database with fast I/O. Finally there are the graphical user interfaces
written in PinK - a Tcl/Tk extension that allows easy access to
Dad and Adamo objects. PinK GUIs form a particular kind of
Dad clients. The other two kinds of clients are hardware and monitoring
clients. Hardware clients report the status of a detector component to a
Dad server or communicate a command from the server to the hardware.
Monitoring clients analyse the contents of a Dad server according to a
set of rules and convert these into a status message.

The Hermes online monitoring system meets the requirements:

Status data about the experiment are stored in the same
data model as physics data and can be easily combined with them in a coherent

Expert knowledge can be converted into the rules of a monitoring
client and in this way help to guide the shift crew.

Any remote machine on which PinK has been installed can
display the same status information as the control room monitors,
allowing experts to monitor their equipment from their home institutes.
The possibility to directly include PinK interfaces in Web pages
in the future is being explored.