In the commissioning run P3, the MDT system will include Sectors ??? from the Barrel, ??? sectors of the big wheel sides A and C from the Endcap and the EIL4 chambers from sectors ??? both A and C sides. In order to run the system successfully, it is necessary to ensure that the chambers satisfy the following checks:

  • Power Supply: LV and HV;

  • Gas

  • Initialization

  • TDAQ software setup

  • Monitoring: GNAM and DQMF

Power Supply


The MDTs require low voltage (5V) for the electronics and high voltage (3080V) that is applied to the tubes. These are supplied by power modules located in miniracks in UX15 and controlled from USA15. A PVSS interface integrated into the general ATLAS DCS controls and monitors the power supply remotely, recording a history of changes in voltage and current.

From the control room, use the DCS GUI that may be accessed directly from the DCS Menu. A link is also available from the Muons Menu. The system that will be used in the final configuration is the DCS FSM running on the machine cerntsatldcs01. If you select DCS FSM Screen, you should be connected remotely to the relevant machine.

If you are prompted to login to the remote machine and do not have an account, you can access the information about power supplies using:

Username: mdt-ps

password: Muon_ux15

Then select the FSM application and start the GUI.

The root account allows the user to view the status. However, in order to make changes, it is necessary to use the individual login and password (same as Point1 account). In the top left section of the GUI, a tree is displayed. Select MDT and then Barrel A, Barrel C or Endcap C.

Turning ON Low Voltage

In M5 the LV is available for Sectors XXX in the Barrel A and C and Sectors XX in the Endcap A and C and EIL4 chambers for Sectors XXX $5$, XXX and XXX both A and C.

In the DCS GUI, there is a color scheme for the STATUS and the STATE (see table 1).

Color Code Status State
green OK READY (HV+LV)
yellow WARNING -
blue - OFF

The LV can be turned on by changing the state for the whole subsection next to the name of the subsection on the tree on the top left part of the GUI (this changes the state for all chambers in that subsection, so only chambers that should be modified should be included). Alternatively, the chamber state can be modified on an individual basis. The trip current for the low voltage should be set to 15A.

Turning on the HV

Before turning on the HV, ensure that the gas situation is satisfactory. Please see the gas section in this manual for more detailed information.

HV is available for Sectors XXXX

If the HV is off and the chambers have adequate gas, the HV can be turned on using the DCS GUI. The trip current should be raised to 25\muA while turning on the HV. Once the full voltage is reached, the trip current should be lowered to 5\muA, and checks should be made to ensure that the current is close to zero.

In case the DCS GUI does not work, it is possible to access the mainframe directly from a terminal with the command:

telnet 1527

when prompted to log in, use:

Login: admin

Password: admin

Use the tab button to open the Menu and select channels. Then scroll down (use the up/down arrows) to the desired module and channels and turn them on/off using the space bar. To exit, use the tab button to open the Menu again and select Log Out.



The MDT chambers operate with a mixture of Argon (93%) and CO_2 (7%) at a pressure of 3 bars. The gas is monitored in racks in UX15 that are connected directly to all the chambers, and these racks are then connected to the broader gas system. There is a PVSS interface in order to control and monitor the gas system remotely. This has been integrated into the general ATLAS DCS and may be accessed in the Control Room under the Muon Menu MDT DCS select MDT DCS FSM).


The MDT chambers are initialized via DCS. The configuration parameters are read from the configurations database and input into a JTAG string that is sent out to the chambers. The chambers should be initialized once the electronics have power (LV on, see previous section on power supply).

Nine PCs are used for initialization (4 for the barrel, 4 for the endcap and 1 spare). These PCs are called pcatlmdtmdmX where X =1-9. These machines may be accessed remotely (in the control room, there is a link from the Muons menu) and the login for these machines is:

Username: *Login: mdmdcs

Password: p!@$\#\$5678$ (NOTE: @$\#\$$ is SHIFT$+1234$)


The PCs work in parallel (so chambers may be initialized simultaneously from different PCs), but there is no single interface to all the PCs yet (so the initialization process should be initialized from all the PCs connected to the desired set of chambers). The chambers used in P3 that are connected to each one of the PCs are:

  • Barrel Side A and C: pcatlmdtmdm1 to pcatlmdtmdm4 (sectors 3-10 A and C sides) MANCANO ALTRI SETTORI XXXX

  • Endcap Side A: pcatlmdtmdm 5 (sectors 1 - 16 ) MANCANO ALTRI SETTORI XXXX

  • Endcap Side C and EIL 4 Side A: pcatlmdtmdm 6 (sectors 1 - 16 ) MANCANO ALTRI SETTORI XXXX

  • EIL 4 Side C: pcatlmdtmdm 7 MANCANO ALTRI SETTORI XXXX

Once logged into the relevant PC, the DCS initialization panel should be displayed. It may be necessary to select the FE control panel. Then select all the sectors and sides to be initialized, and click Init All. If the initialization fails, click Init Failed and this command will only initialize chambers that are in the FAILED state. It is possible to initialize a single chamber by selecting it and then clicking on Initialize. The state will be updated on the general panel.

In the case of the barrel, an additional check on the initialization may be performed in USA 15 . Once a chamber has been initialized, a green LED should appear next to the corresponding MROD channel (top six connectors of the MROD boards in USA 15 ). The correspondance between the chambers and the MROD channels are described in the manual 2003 - 023 .pdf. In the case of the endcap, the green LEDs only turn on in the Configuration step of data acquisition.

For barrel sectors 3 - 6 , the MRODs used are located in the top and middle crates of the first and third racks (counting from the entrance to USA 15 ). The first two inputs from the top are the BI chambers, the middle two BM chambers and the bottom two the BO chambers.

TDAQ Software

The Trigger and Data Acquisition (TDAQ) system allows for taking data and selecting events using the trigger. During the commissioning runs, the shifter must configure, control and monitor the MDT system, and these tasks are carried out using the online software.

A feature of the system is that it is partitionable, meaning that it can be sub-divided into independent but fully-functional units. The MDTs can thus take data independently and in parallel with other sub-detectors (standalone mode) or combined with other parts of the detector (combined mode). During the commissioning milestone there are periods devoted to independent running, either to debug problems or to ensure stable and good quality data taking (e.g. calibration runs). However, since the goal is to run integrated with other parts of the detector, the combined software is typically run from the central station and the individual shifters may monitor the run in spy (observer) mode.

DAQ Panel Basics

On the left side of the DAQ Panel, specify the setup script used and the online database file used for the run. In particular for the M 5 combined run select:

Setup scripts: /det/tdaq/scripts/setup\_TDAQ\

Database File: /db/tdaq-01-08-03/combined/partitions/combined-postM 5 .data.xml

Click on Get Partition, select the partition named muon\_combined and then click Read In. Under the main menu, SpyIGUI opens a read-only copy of the central TDAQ GUI. * DAQ Panel:

The *OKS button opens the OKS data editor with the current partition to edit the configurations database. If settings in the database are changed and the TDAQ GUI is running, it is necessary to reload the database from the command toolbar of the TDAQ GUI (blue arrow on the right of the partition name) when all components are in NONE or INITIAL state. The MRS button opens the Message Reporting System (this is also available from the TDAQ panel). This monitor presents all the error messages from all components in the DAQ system and provides capabilities to filter messages.\ In the monitoring tab, the OHP button opens the Online Histogram Presenter and {\bf OH} opens a root TBrowser with the GNAM histograms (more information below under Monitoring, GNAM). The DQMF button runs the Data Quality Monitoring Framework that consists of quality algorithms that applied to GNAM histograms (see below the section under Monitoring, DQMF). The {\bf IS Monitor} (Information Service Monitor) button shows detailed information for run parameters, run control, monitoring, and PMG. This feature is also available from the TDAQ GUI. The Data Flow (DF) key provides similar information as the TDAQ GUI Data Flow tab (see next section on TDAQ Panel). The {\bf IS Logger} opens a GUI for IS. DO NOT CLICK! Crashes often with an uncloseable window.

The BUSY button opens the CTP busy panel.

TDAQ Panel Basics

The TDAQ panel is divided into three main section. The left section is the run control panel that displays the state of the system, the commands that are available (Boot, Config, Start, Pause, Stop, Unconfig, Shutdown). This section also contains a summary of Run Information such as the Run type, the Run number and the rates and number of events at different stages.

The bottom section is the MRS window that displays the (error, info and so on) messages. In the GUI toolbar the user can select to display the messages in the window in LONG or SHORT (this is the default) form. A separate MRS window may also be opened from the main DAQ panel.

On the top right side, the TDAQ panel has multiple tabs with information for running and monitoring. The tabs that are relevant for the MDTs are:

  • Run Control tab: This tab provides information about the run control. It is divided into two parts: the left side displays the tree of the segments in the partition and by expanding it the user can see the applications and controllers. The right side has three tabs on the bottom including the Status and Commands available to the user and information regarding the database configuration.
  • Infrastructure tab: This tab appears at the startup of the TDAQ GUI. Right-click on field to view the setup and application logs.
  • DataFlow tab: The information provided here is similar to Data Flow (DF) under the Information Service (IS) Monitor. All ROS segments show the number of L 1 events. The Data Flow Manager (DFM) segment has the number of L 2 accepts/rejects and L 2 and Event Filter (EF) rates.
  • Run Parameter tab: The Filename Tag is used to tag groups of runs. Typically during M 5 the tag m 5 -combined is used. Use tab to Enable/Disable recording of data.
  • MRS tab: This tab allows the user to configure filtering and formating of errors and warnings in TDAQ GUI lower screen.
  • PMG tab: The Process Manager tab allows the user to view and manually start/stop processes on online computers.
  • Segment and Resource tab: This tab can be used to enable/disable segments and subtrees by right-clicking on them. Note that the changes must be updated to the database (click on the button below) before running. Beware that it is crucial to check that the changes have actually been implemented in the database after updating since this operation sometimes fails without warning.


A more detailed Control Room Quick Guide to the IGUI is available with additional instructions.

MDT Standalone

In order to switch from a global run into MDT standalone mode running with the barrel, open a terminal as muondaq and type:




In order to run with the endcap, type instead:




The barrel and endcap cannot run in combined standalone mode, but both these partitions can be run simultaneously. When the GUI has loaded, in the Segment and resources tab select the MDT RCD (select MROD channels), MDT ROS, TTC and EB (Event Builder) segments and channels that you want to run. Disable the other segments. Make sure that you have the MROD HW\_InputChannels desired enabled. Also select the appropriate EB channels that are included in the run. The names of the enabled channels should match the MROD crate names. Commit the changes to the database. Then return to the Run Control tab and follow the steps boot, configure and start.

In order to enable/disable a chamber, open the OKS data editor, select the MRODX object corresponding to the desired input channel, the mroChanMask is the mask of chambers to be read out, from the most significant to the least significant bit. Change accordingly and save changes.


A variety of tools are available to monitor chamber behavior and detect problems with the detector hardware or in data-taking. Histograms are produced online using GNAM and an online histogram presenter (OHP) facilitates their viewing. In addition, quality algorithms are applied to the GNAM output using DQMF, providing error and diagnostic messages. The monitoring information is displayed in separate interfaces.

* OHP1:

  • GNAM

GNAM is an Online Monitoring structure that allows monitoring of detector status and running conditions. For the MDTs during M 5 , GNAM has been implemented at the ROD level and provides histograms such as TDC and ADC spectra, hits per chamber and tube and so on. In order to setup gnam it is necessary to provide chamber and run information. Before starting the run check and/or correct the files located in the directory /db/tdaq-01-08-03/muons/data/gnam\_setup/mdt.


In particular, chambers not included in the run should be commented out and the missing chambers should be added. It is critical that the user modifies the runtype flag depending on the type of run ( 1= noise; 2= cosmics). GNAM histograms are available:


The Online Histogram Presenter (OHP) is a stand alone application displays the GNAM histograms, enabling the user to browse the histograms and display selected groups of histograms to be checked during the run. In order to configure OHP, in the main DAQ Panel select the file:

OHP Opt: -c /db/tdaq-01-08-03/muons/segments/DQM/MDT.ohpconf.m5.xml -e ohpcommands.

Select Read Info and select OHP in the monitoring tab. The OHP panel is organized in browser mode and with tabs which provide overview information per crate and per chamber.



Run information is recorded in the ATLAS Elog, as well as a record of the start and the end of each run. The Elog can be accessed from outside CERN (read-only access) at: and from inside the CERN network at: For read-only access user: atlas and password: insider can be used. In order to enter information request a password to

Phone Numbers

Questions? These are the MDT experts available for P3. Additional areas of expertise are listed in parenthesis.

Sotiris: 163046 (Muon Run Coordinator)

Ludovico: 163664 (Barrel)

Fabio: 164492 (Barrel)

Joao: 162797 (Endcap)

Joerg: 163397 (Gas)

Gabriella: 162256 (GNAM)

Alberto: 162877 (DAQ)

Enrico: 162197 (Absolute Muon DAQ Expert)

Henk: 165351 (MROD and JTAG Initialization)

Shulamit: 165153 (DQMF)

Alberto: use English for your comments!

I'm just testing if I can modify this page.

-- SilviaFranchino - 07 Feb 2008

Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng Elog.png r1 manage 224.4 K 2008-02-13 - 11:48 SilviaFranchino ELOG
PNGpng InitPanelP2.png r1 manage 74.5 K 2008-02-13 - 11:50 SilviaFranchino init Panel
PNGpng M5_DAQPanel.png r1 manage 230.9 K 2008-02-13 - 11:53 SilviaFranchino DAQ Panel
PNGpng M5_TDAQPanel2.png r1 manage 77.9 K 2008-02-13 - 11:54 SilviaFranchino TDAQ panel
PNGpng OHP-BA02-Overview.png r1 manage 84.0 K 2008-02-13 - 11:55 SilviaFranchino OHP1
PNGpng mdtpowersupplycontrol.png r1 manage 164.9 K 2008-02-13 - 11:52 SilviaFranchino DCS Power supplies
PNGpng mdtps_bwaps.png r1 manage 166.5 K 2008-02-13 - 11:52 SilviaFranchino DCS Power supplies Big Weel
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