- HV systems
Most of the detectors use CAEN
HV crates for their HV systems. The following models of CAEN crates are used:
SY127, SY403, SY527 and SY1527. While for the latter, the slow control is
done using CAEN OPC server, with Ethernet connection to the crate, in the
case of all the other older models SLiC + DIM packages are used. SLiCs run
either on VME processor or PC Linux platforms. The system is split in 5 CAENet
Straw and Silicon detectors use
ISEG HV modules. These are controlled using a COMPASS-made SLiC,
compiled as OPC Server, running on Windows 2000 platform. There are 2
CANbus branches in the system, one for each detector.
More details on the
ISEG for Straws
implementation, and on the
ISEG for Silicon implementation.
Other detectors use home-made HV power
supplies, which are not integrated in the DCS. In the case of ECal2 an
alarm system was installed, to provide signal to DCS in case the HV
switches off (using an ELMB analogue channel).
- LV systems
Straw, RICH and SciFi detectors use
Wiener LV power supplies. These were integrated in the DCS
during 2006 Run, using the Wiener OPC Server. The system will be split
in 2 CANbus branches, one for Straws and SciFiW, and another to RICH.
Other detectors use home-made LV
power-supplies. In the case of MWPC, MW1, MW2 and W45 these are monitored
using ELMB analogue channels. The system is distributed per more than 10
ELMBs, in 2 separate CANbus branches.
- Crates control
The Experiment uses Wiener
fan-trays for the VME 9U crates. These are controlled in the DCS using
the Wiener OPC Server. The connection is done using one
CANbus into a Kvaser PCI-CAN Q card interface port.
Most of the detectors' gas systems are
controlled using 3 PLCs. There is monitoring of the status of
the PLCs and compressors, as well as gas fluxes and mixtures, in PVSS via an
OPC Server. The software for the PLCs is by Schneider Automation, while
the OPC Server used is OFS (from Modicom Telemechanique). Connection uses a CANbus
into one port of a Kvaser PCI-CAN Q card.
Details on the design of the gas
systems for COMPASS (PLC2: RICH, MWPC, STRAWs) can be found
The monitoring of slowly varying
parameters like temperatures, humidities and atmospheric pressure, as well
as other parameters like magnetic fields (measurement using Hall probes),
and LV power supplies and VME power supplies, is done using ELMB ADC
Generic information about the ELMBs.
Description of the ELMB system in COMPASS
for the 2006 Run period.
Racks cooling system (for the electronics
racks and RICH detector).
2 UPS units are connected to the main
DCS computers in the Experiment: pccompass04, pccompass03 and na58pc014.
They allow for the correct shutdown of PVSS in case of a sudden power cut,
preventing corruption of PVSS databases.
Technical details on the UPS's installed.