Coverity fix for uninitialized variables and check for returned null value
[u/mrichter/AliRoot.git] / MUON / READMEmchda.txt
b9f858e1 1// $Id$
d0f1f198 5\page README_mchda Tracking DA
b9f858e1 6
a4c42212 7The detector algorithms are implemented for the Muon Tracking in the AliRoot framework.
8We currently have 3 DAs for MCH :
10- MUONTRKPEDda.cxx for PEDESTAL runs, running at the end of data taking on each LDC.
11- MUONTRKGAINda.cxx for CALIBRATION runs, running at the end of data taking on each LDC.
12- MUONTRKOCCda.cxx for PHYSICS runs, running during data taking on each LDC.
b9f858e1 14\section da_s1 The Muon Tracking Calibration
a4c42212 16The Muon tracking chambers needs three types of calibration in order to work properly
17(to be more precise pedestals are required, gains are needed to get the best charge measurement possible, and the occupancy
18 is needed in order not to spend all the reconstruction time in hot-spots).
b9f858e1 19
20\subsection da_ss1 Pedestals
22The front-end electronics performs an online zero suppression using a threshold level.
23Those threshold levels for all channels (~ 1 million) have to be computed in a dedicated
f3cfa63e 24PEDESTALS runs. During this runs the zero suppression is OFF and the pedestal level and the noise is obtained for each channel. The threshold for the FEE is obtained adding the pedestal level to 3 sigmas of the noise.
b9f858e1 25
26The typical ECS sequence for pedestals is :
28- Switch ON the electronics LV
29- Boot the CROCUS
30- Configuration
f3cfa63e 31- Saving Configuration in an ascii file then transferring in the File eXchange Server (FXS)
b9f858e1 32- Zero suppression OFF
33- Data taking (typically 400 events)
34- The DA computes the mean and sigma (it runs in each LDC)
35- The DA writes one ASCII file per LDC with the results in the File Exchange Server
f3cfa63e 37Then the SHUTTLE process the ASCII files and store the result on the OCDB (Keyword=PEDESTALS)
38Only configuration files corresponding to a change of the Muon Tracker configuration are written in the FXS (Keyword=CONFIG).
b9f858e1 40
41\subsection da_ss2 Electronics gain
43In order to perform the required spatial resolution or the tracking chambers (~ 100 microns),
44we need to calibrate the gain of each channel. The gain is computed using dedicated runs where
f3cfa63e 45a signal (DAC) is send to the chambers FEE.
b9f858e1 46
47The typical ECS sequence for calibration is :
49- Switch ON the electronics LV
50- Boot the CROCUS
51- Configuration
52- Zero suppression OFF
f3cfa63e 53- Loop of 11 data taking (typically 400 events) each with a different signal (DAC=0-200- 400-800-1200-1600-2000-2500-3000-3500-4000)
b9f858e1 54- The DA computes the mean and sigma (it runs in each LDC) for each run
f3cfa63e 55- At the end of the last run, the DA computes, by using a fitting procedure, linear and parabolic gain parameters, and writes results in one ASCII file per LDC. Every ascii files are transferred in the FXS.
b9f858e1 56
f3cfa63e 57Then the SHUTTLE process the ASCII files and store the result on the OCDB (KEYWORD=GAINS)
b9f858e1 58
a4c42212 59\subsection da_ss3 Occupancy
61For PHYSICS (or STANDALONE) runs, the MUONTRKOCCda, which is a monitoring DA, keep track of how many times
62 each channel has been hit during the run. The output is an ASCII file containing the needed information to
63 compute the occupancy values. This file is written to the DAQ FXS so the SHUTTLE can transfer it to the OCDB.
b9f858e1 65\section da_s2 Using the DA Online
f3cfa63e 67\subsection da_ss1 Pedestals
69The syntax is: MUONTRKPEDda.exe "raw data file"
71Two input files located in the DAQ Detector database (DetDB) are needed:
f9e83f1d 73- muontrkpedvalues is built in flight in (ECS script) and contains one parameter "config" :
f3cfa63e 74 config = 1 if configuration file has to be used (OnLine case)
1ccd531d 75 config = 0 if not (OffLine case for the time being)
f9e83f1d 76
1ccd531d 77- config_ldc-MTRK-S3-0 : configuration file name corresponding to MuonTracker Station 3 if (for example) DA is running on ldc-MTRK-S3-0
f3cfa63e 78
18ec51a0 79- DA validation: see Header of MUONTRKPEDda.cxx for reference run, and corresponding input mutrkpedvalues and configuration files are located in path=/afs/
f3cfa63e 81\subsection da_ss2 Electonics gain
83The syntax is: MUONTRKGAINda.exe "raw data file"
85Two input files located in the DAQ Detector database (DetDB) are needed:
f9e83f1d 87- muontrkcalibvalues: which attributes to each run index (1->11) its corrresponding DAC value. The other parameters are used to tune the fit procedure (for expert). The last parameter indicates the number of events to be read: if "0" all events in the run are read, if not the parameter indicates the maximum number of events to be read.
f3cfa63e 88Default values are listed below
911 0
922 200
933 400
944 800
955 1200
966 1600
977 2000
988 2500
999 3000
10010 3500
10111 4000
baf1a7a0 108\endverbatim
f3cfa63e 109
1ccd531d 110 - config_ldc-MTRK-S3-0 : configuration file name corresponding to MuonTracker station 3 if (for example) DA is running on ldc-MTRK-S3-0
f3cfa63e 111
18ec51a0 112- DA validation: Header of MUONTRKGAINda.cxx shows the list of the 11 reference runs, and corresponding input mutrkcalibvalues and configuration files are located in path=/afs/
f3cfa63e 113
114\section da_s3 Using the DA Offline
116The DAs normally runs with a RAW data DATE format as input
117The development of an Offline version is under way.
119Nevertheless, Pedestal runs can be analysed locally, but without detector configuration file. If you get a file in root format (e.g. from alien), you can de-rootify it using the
120 "deroot" program which is part of aliroot.
121Note that PED and GAIN DAs work with ROOT input files as well.
b9f858e1 123You have a line command help. To have it just type :
a4c42212 126> MUONTRKPEDda.exe -h
b9f858e1 127
a4c42212 128******************* ./MUONTRKPEDda.exe usage **********************
f3cfa63e 129Online (called from ECS) : ./MUONTRKPEDda.exe <raw data file> (no inline options)
131./MUONTRKPEDda.exe can be used locally only with options (without DiMuon configuration file)
a4c42212 132./MUONTRKPEDda.exe -options, the available options are :
f3cfa63e 133-h help (this screen)
b9f858e1 134
135 Input
f3cfa63e 136-f <raw data file> (default = )
b9f858e1 137
138 Output
f3cfa63e 139-a <Flat ASCII file> (default = MUONTRKPEDda.ped)
b9f858e1 140
141 Options
f3cfa63e 142-m <max date events> (default = 1000000)
143-s <skip events> (default = 0)
144-n <max events> (default = 1000000)
b9f858e1 146\endverbatim
a4c42212 148
b9f858e1 149\section da_s4 In case of trouble
151Please contact :
f3cfa63e 153Jean-Luc Charvet :
b9f858e1 154or
155Alberto Baldisseri :
a4c42212 156or
157Laurent Aphecetche : (for OCC DA)
b9f858e1 158
f3cfa63e 159This chapter is defined in the READMEmchda.txt file.
b9f858e1 160*/