use same DAC-HV value relation as for calibrations + voltage values stored as floats...

[u/mrichter/AliRoot.git] / EMCAL / SMcalib / README

silvermy@ornl.gov, Oct 9, 2008: 
This README file and the associated macros are meant to help with the SuperModule calibrations.

The steps below indicate how a set of bias
values (fixed voltage, or V30 for each APD, and a 2nd iteration with gain balancing)
for a SuperModule can be created.

The necessary information that would be needed to complete the steps would be
A) APD calibration info (csv file) - from Catania or Houston
B) Info on which APD goes where in the different StripModules - and
where these StripModules end up in the SuperModule.
C) [for the balancing] A file obtained from the first analysis iteration regarding
how the gains should be modified, for each tower.

/David Silvermyr

0) Compile the help classes in root or aliroot:
----------------------------------------------
root [0] .L AliEMCALMapAPD.cxx+
root [1] .L AliEMCALCalibAPD.cxx+

1) Generating an APD map: normal use case in a root macro for your SuperModule
-------------------------
//a) create a dummy space in memory:
  gSystem->Load("AliEMCALMapAPD_cxx");
  AliEMCALMapAPD *mapAPD = new AliEMCALMapAPD();

  Int_t iSM[2] = {0,1}; // allow for two SuperModules
  mapAPD->GenerateDummyAPDInfo(1, iSM); // space for one SuperModule, with number iSM[0] = 0

//b) overwrite this memory with the actual values for the StripModules; one line for each of the 24 stripmodules (0-23)
  mapAPD->ReadMapAPDInfoSingleStripBasis(0, 21, "APDStripModXY.txt"); 
// "XY" should perhaps be F5 for 5th stripmodule from Frascati or something like that. F=Frascati, W=WSU, N=Nantes, C=Catania

//For a "APDStripModXY.txt" file, 48 lines with 3 fields:
//StripColumn StripRow APDNum
//is expected..

//c) write out the map for column, row, APD for the whole SM:
  mapAPD->WriteMapAPDInfo("APDSuperModY1.txt"); // Y=Yale, G=Grenoble

2) Generating a file of V30 bias values for each tower:
------------------------------------------------------- 
# arguments are:
1: input APD database csv file
2: APD map file - which tower is where in the SuperModule; from step 1) above. 
3: defaultVoltage - use 390 if no settings can be found for some APDs
4: outputfile

root -b 'WriteBiasV30.C("APD-database.csv", "DummySuperModAPDMap.txt", 390, "BiasV30.txt")' -q 
# aliroot also works instead of root; as you prefer

3) Optional - e.g. in case you don't have the whole SuperModule APD map or what not 
Generating a file of the same bias value for each tower:
---------------------------------------------------------- 
root -b 'WriteBiasFixVoltage.C(390, "Bias390.txt")' -q # aliroot also works..

4) Generating a file of new bias values for each tower:
- based on existing file, and a suggested gain factor change, to obtain a balanced setup
------------------------------------------------------------
"GainChange.txt" here contains a factor for each tower: factor 0.9 would mean a reduction
by 10% and factor 1.1 would mean an increase by 10% relative to the file used previously,
in this case BiasV30.txt.

root -b 'WriteNewBias.C("APD-database.csv", "DummySuperModAPDMap.txt", "BiasV30.txt", "GainChange.txt", "NewBias.txt")' -q # aliroot also works..

5) Converting a bias value file to a set of files that can be used by DCS/RCU: 
-----------------------------------------------------------------------------
Arguments are:
1: input file with voltage per tower
2: output directory for scripts
3: [optional: put a non-zero value there to also ask for the values to be read back at the end of the 'set' files]

mkdir APD # create output directory
root -b 'DCSGenerateAPD.C("NewBias.txt","APD")' -q

The result should be that 1 'set' and 1 'read' file for each FEC should have been created in the directory APD/.

6) Use the newly produced files:
-------------------------------
Copy the files, and possibly biasSetup.sh into your DCS nodes 
(e.g. with scp, or better use nfsmount on DCS cards to see some directory
on your DAQ computer, if possible),
rcu_0 files should be readable by RCU0 DCS, and rcu_1 files should be readable by RCU1 DCS.

Then, on the DCS card, you can do something like:
cd /dcs
./biasSetup.sh 0 # argument is RCU (0 or 1),; we need to tell each RCU who (s)he is..