-- EstherBabetteMenz - 2022-03-09

Experiment Control and Data Acquisition System

This is a short guide the the control and data acquisition (DAQ) system used for DR experiments at CRYRING@ESR.


The MBS (Multi-Branch System) software directly talks to the data-acquisition hardware. It has been developed and is maintained at GSI. Comprehensive documentation is available here.

Before you start the MBS you have to start the RFIO server (if it is not already running). Open a terminal (Terminal 1), ssh to atppc025 and go to the data directory (new: /u/cry_exp/Beamtimes/<date_ion> (e.g. 202203_Li+); old: /data.local1/<experiment number> on lxg1231) and type:


Now open a separate terminal (Terminal 2) to start the MBS:

ssh cry_exp@r4l-67
cd <working directory>
mbs -dabc

At the MBS prompt you now type

mbs > @startup

and connect to the RFIO server with

mbs> connect rfio atppc025 -DISKSERVER

MBS should now be running. All other actions, e.g. opening files and starting the DAQ, can be done from the GUI.



The YRDRgui can be used to prepare and handle electron-ion collision experiments at the CRYRING electron cooler. The gui facilitates the creation of control files (DAC ramp files) for the sequences of voltages to be applied to the high-voltage amplifiers of the electron cooler during a measurement. The gui can be launched from any directory by using the command YRDRgui. On exit, the gui stores all current input values on disk, such that they will be retrieved if the gui is restarted from within the same directory.

At startup the user is prompted for an ELOG (electronic logbook) username and an ELOG password. This is required for the automatic generation of ELOG entries. The credentials can be reentered by changing the "ELOG" text at the bottom left of the gui window.

The GUI provides input fields for various quantities that are required for the generation of ramp files. To get more information about the individual fields hover over them with the mouse pointer. The color of the input depends on the choices being made. Gray fields are ignored in the creation of ramps, yellow fields contain values that are calculated internally and that cannot be changed by the user. Press return after the input of values. After having hit return the values will be used in the internal calculations. This may results in changes in one or more yellow fields. The input is checked for validity and consistency. If an error is detected the corresponding value will turn red and an error message will be displayed. The latter will vanish after correct values having been entered.

Clicking the button make ramp file creates a set of files with the extensions %.rmp, %.ecm, and %.txt. The program checks if a ramp file already exists in order to avoid overwriting of files. If the ramp file name is displayed in red, choose a file name (usually by increasing the number).
Clicking the button install ramp file sends the %.rmp file to the microprocessor that controls the HV amplifier and sends the substep timing values to the microprocessor that controls the sequencer. The %.ecm file provides the center-of-mass energy axis for the Go4YRDR analysis (see there for details). At the same time an entry ("new DAC ramp") is made in the ELOG using the content of the %.txt file. These entries are a good source of information on the values that were last used, e.g. in case of a crash. Automated entries are also created whenever a file is openend/closed and the DAQ started/stopped.

A file can be opened (button 'open file' at the top) once the the ramps is installed and the MBS system is running. After the button has turned orange (this make take a moment) the data acquisition can be started with 'start acq'. Once the data acquisition is running you can few the collected data using Go4 (see below).


The online analysis Go4YRDR is executed in the Go4 environment (see here for more infos). To start it up type

go4 &

on the command line. After Go4 has started launch the analysis (Analysis → Launch Analysis in the menu). The following window should pop up:


Fill in the Go4YRDR directory (full path) as shown in the example. Make sure that lib and libGo4UserAnalysis are selected as shown. Hit the button with the green check mark to actually link the analysis to Go4.

The analysis must be configured as shown in the ’Analysis Configuration’ window below:

  • ’Step Control’ : Check ’Enable Step’ and ’Source’, uncheck ’Store’
  • ’Event Source’ : MBS Stream Server
  • ’Name’ : r4l-67 (small "L", not number "1", adjust as needed.)
  • ’Auto Save File’ : disabled (no check mark at ’enabled’)
After configuration of the analysis click ’Submit’. This initializes all histograms and reads the %.ecm file, which can be specified as a parameter. All Parameters can be entered in the ’Parameter Editor’ (figure below), which can be found in the ’Browers’ field on the far left under Analysis→Parameters→YRDR. If you have created a new ramp file make sure that you are using the correct .ecm file. If you change an entry in the ’Parameter Editor’ click ’Submit’ and then ’Submit’ again in the ’Analysis Configuration’ window. When this is done you can start the analysis (Analysis→Start in the menu).


  • Most problems are related to the auto-save file ~/Go4YRDR/Go4AutoSave.root. This file can be safely deleted. In case of trouble, quit the Go4 programm delete this file and restart again.
  • Be patient and avoid pressing buttons multiple times. This can lead to awkward conditions and may even cause the program to crash.
  • In case of a crash, kill the remaining Go4processes (check with ps) using the terminal commands killall MainGo4Gui or killall go4.

See also

Topic attachments
I Attachment Action Size Date Who Comment
Go4AnalysisConfig.pngpng Go4AnalysisConfig.png manage 101 K 2022-03-23 - 14:18 EstherBabetteMenz Go4 Analysis Configuration window
Go4LaunchAnalysis.pngpng Go4LaunchAnalysis.png manage 82 K 2022-03-23 - 14:19 EstherBabetteMenz Go4 Launch Analysis window
Go4ParameterEditor.pngpng Go4ParameterEditor.png manage 515 K 2022-03-23 - 14:20 EstherBabetteMenz Go4 Parameter editor
YRDRgui.pngpng YRDRgui.png manage 1 MB 2022-03-23 - 15:20 EstherBabetteMenz YRDR gui for experiement control
Topic revision: r7 - 2022-03-26, MichaelLestinsky - This page was cached on 2022-07-02 - 08:50.

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