Liverpool Clean Room

Software environment


Online software is in:


The tracker DAQ repository is:


Before using any online software, set up the environment:

source gm2-tracker-readout-daq/software/


Offline software is in:


Before using any offline software, set up the environment:


Low voltage

To switch on the low voltage, use the following commands:

TODO Update this for new LV

Don't leave the system on unless it is being used.

DO NOT switch on unless the FLOBBER fan cooling is on.


Initial set up

To totally start again with your MIDAS set up (only do this if it all goes horribly wrong):

source gm2-tracker-readout-daq/software/ #If not done already hard_clean #Clean any existing experiment
odbedit -c "load $MIDAS_ONLINE/data/cleanODB_lpoolOct2016.odb" #Load clean ODB
$MIDAS_ONLINE_BIN/ start #Start MIDAS experiment
firefox $MIDAS_HOST:$MHTTP_PORT & #Open experiment web GUI

Start/stop MIDAS

The steps above are just for the initial set up. In general MIDAS will stay running, but if you need to stop/start it again (e.g. after PC reboots): stop    #Stop MIDAS start   #Start MIDAS

To view MIDAS web GUI (where you do everything), go to .

Starting frontends

To start a frontend, go to the MIDAS web GUI and click the Programs tabs. It shows a list of frontends, and has buttons to start/stop each of them.

The frontends should be started in the following order:

  1. LowVoltage01
  2. SlowControls01
  3. EBuilder
  4. MasterGM2
  5. StrawTrackerDAQ

They should be stopped in the reverse order.

Starting runs

The MIDAS web GUI has a Start button for starting runs. Press this and leave the default run number, then click OK to start run. Amazingly enough click the Stop button to stop it.

Note that starting the run takes around 30 seconds, so be patient! The box in the top-left of the GUI will go green once the run has fully started.

DAQ config

The configuration of StrawTrackerDAQ is defined in the MIDAS Online Data Base (ODB). TO get to it, click the ODB button on the MIDAS status page.

The thing you are most likely to change is straw electronics configuration. THis can be found in:


Within this directory the subdirs are hierarchical in the msae way as the electronics themsleves.



Many MIDAS problems can be solved with the following command: hard_restart    #Restart MIDAS after some cleaning

Noise scans

Noise scans can be used to check what ASDQ discriminator threshold (DTHRThreshold param in DAQ config XML file) needs to be used to exclude noise.

To run the scans:

python $GM2_TRACKER_DAQ_SRC/test/ -lb <LB path>

e.g. for logic board 0

python $GM2_TRACKER_DAQ_SRC/test/ -lb AMC13-0/FC7-0/LB-0

Change the following parameters in to set the min and max thresholds and step size for the scan (units are mV):

  • minThreshold
  • maxThreshold
  • thresholdStepSize

3) Make plots

Make plots from the results using:

root -l $GM2_TRACKER_DAQ_SRC/test/plotNoiseScanResults.C

The plots will also be saved as NoiseScanResults_TDC0.png, etc (one per TDC).


ROME is used for DQM (Data Quality Monitoring).

The DQM repository is:


The tracker DQM is in:


Before using the DQM, set up the environment:

cd /hepstore/g2ucl/productionDAQ/online/gm2dqm-gm2-dqm/tracker

To run it offline (e.g. on a MIDAS file after the run has finished):

$GM2DQM_DIR/tracker/dqm/strawtrackerdqm.exe -i $GM2DQM_DIR/tracker/dqm/romeConfig.xml -m offline -pi $MIDAS_ONLINE_DATA -po /tmp -ph /tmp -r <run num>

where <run num> is the run number you want to analyze.

To run it online (e.g. during MIDAS runs):

$GM2DQM_DIR/tracker/dqm/strawtrackerdqm.exe -i $GM2DQM_DIR/tracker/dqm/romeConfig.xml -m online -pi $MIDAS_ONLINE_DATA -po /tmp -ph /tmp

Once ROME is started in online mode, it will automatically start plotting each time a MIDAS run is started.

Offline analysis

To process a MIDAS file in the offline analysis world, first set up the offline environment as described above and then run the following FCL files:

MIDAS-to-art / Unpacking :

gm2 -c $MRB_SOURCE/gm2unpackers/fcl/StrawUnpacker.fcl -s $MIDAS_ONLINE_DATA/run<run num>.mid.gz

e.g. for run 1:

gm2 -c $MRB_SOURCE/gm2unpackers/fcl/StrawUnpacker.fcl -s $MIDAS_ONLINE_DATA/run00001.mid.gz

Plot the unpacked events and raw digits:

gm2 -c $MRB_SOURCE/gm2unpackers/fcl/StrawUnpackerPlots.fcl -s StrawUnpacker.root

TODO Below this still needs updating before it can be used

Raw to digit conversion :

gm2 -c $MRB_SOURCE/gm2tracker/fcl/LiverpoolRawtoDigits.fcl

Digit plotter:

gm2 -c $MRB_SOURCE/gm2tracker/fcl/LiverpoolDigitsAnalysis.fcl

The result should be a ROOT file called LiverpoolDigitsAnalysis_strawTriggerDigitPlots.root with some histos in it.