VELO Module Laser Test Software

Contents

• Quick Start
• For the more patient
• File check utility

Quick Start

This is how you run the laser test analysis after finishing the the laser scan for a sensor. As an example let's assume you just tested the R sensor of hybrid 59:

• logon to lhcbfe
• cd /lhcb2/user/labdata/laser_test
• • if you use csh: source ./bin/setup.csh
  • if you use (ba)sh: source ./bin/setup.sh
• ltana -hybrid 59 -sensor R

For the more patient

What it does

The software described here is for the laser test analysis and only for the laser test analysis. If you need to produce noise and pedestal data the noise analysis page is what you want.

The laser test analysis does the following:

• search for shorts
• look for dead strips
• write the results to the proper location where the data base expects them
• write out lots of histograms (optional)

Setting it up

The software is installed on lhcbfe in /hcb2/user/labdata/laser_test. The installation will be kept up to date by me. All you have to do to setup the environment for the laser test analysis is this:

• logon to lhcbfe
• cd /lhcb2/user/labdata/laser_test
• • if you use csh: source ./bin/setup.csh
  • if you use (ba)sh: source ./bin/setup.sh

Command line interface

The interface you use when running the analysis is the wrapper script 'ltana'. It provides several options to set output directories, switching on/off certain functionality and so on. After setting up the environment properly (see above), the script (as well as all executables it uses) will be in your path. Just type 'ltana' to run it. If you run it without arguments or with the '-help' switch it will print a list of the available options. The order of the command line options does not matter. Two of them are mandatory, '-hybrid' and '-sensor'. So the most simple command line for analysing laser test data is

• ltana -hybrid <hybrid number> -sensor <Phi | R>

In case things go wrong, e.g. the analysis is suspicously fast, you might want to try some of the available options in order to identify the source of problem:

• -verbosity 4 : gives you a lot of output from the backend programs
• -histograms on : useful if you want to have a look at the raw adc counts
• -histodir <dir> : puts the histograms in <dir>, useful if you do not have write permission in the current directory
• -resdir <dir> : puts the result in <dir> so you do not risk overwriting 'official' results

File Check Utility

There is a small utility program available that allows to check a file produced by the laser test for validity. A file is considered ok if

• it contains more than 8 readable events
• the laser signal position is in 2 strip units of the nominal laser position

Here is how you run it:

• logon to lhcbfe
• cd /lhcb2/user/labdata/laser_test
• • if you use csh: source ./bin/setup.csh
  • if you use (ba)sh: source ./bin/setup.sh
• ltfilecheck <file name> <sensor type>

And some example output:

[rinnert@LHCbFE Sensor]$ ltfilecheck laser_test_adc0_pos0_strip_27.bin R

Output from binary decoder:
===========================

LAST EVENT

Summary:
========

Events in file: 97 --> Ok.
Nominal signal position:   1690.5
Estimated signal position: 1691.05 --> Ok.