MUSR Midas-based Online Data Acquisition System

Last update: May 2014

  System is used for both TD-MUSR and IMUSR



How to Start the DAQ:

  1. Determine your beamline
  2. Log In
  3. Start the MUSR DAQ
  4. Start the Front End
  5. Select TD or IMUSR experiment
  6. Select the Run Parameters
  7. To Start a Run
  8. To Stop a Run

To Restart the DAQ after error:

  1. Kill All DAQ tasks
  2. Start All DAQ tasks
  3. Reboot the Front End (PPC only)
  4. Continue by starting the run as usual


Users' Documents

MUSR run control
Data archiver (mdarc)
CAMP Slow Control

Programmers' Documents

System management

Back to DAQ website



The MUSR data acquisition software runs under linux using the TRIUMF standard  Midas  data acquisition software package. A custom gui (written by D. Arseneau) is provided for MUSR users.

DAQ systems using a VME PowerPC (PPC) has been in use in the three counting rooms (M20,M15,M9B) for some years. A VME VMIC-based system with the latest Midas software has recently (April 2014) been installed in the M15 counting room.  The VMIC replaces the PPC. It is expected that all MUSR systems will run with VMIC in the near future.


The following table summarizes the hardware changes made to the DAQ system in M15 . Changes are highlighted in red.
Installed in Counting rooms M20, M9B
Installed in Counting room M15
Old DAQ hardware
New DAQ hardware
PC P-3-1000
Old host computer (Linux SL4.3), old MIDAS DAQ system
New host computer (SL6)  running latest MIDAS DAQ System
16 Scaler Channels
16 Scaler channels 
16 Output channels 4 Input channelsempty16 Output channels 4 Input Channels
16 Output channels 4 Input channels
MVME2306 power pc
(32Mb memory)
cpu running VxWorks acts as a Midas frontend and Histogram Memory 
512mB, 1.4 GHz
32-bit cpu running Linux acts as a Midas frontend and the Histogram Memory.
VxWorks cpu handles the SlowControls via CAMP. On-board Industry packs handle GPIB, Serial ports etc.
Booted from ram, loads configuration from the linux pc
VxWorks cpu handles the SlowControls via CAMP. On-board Industry packs handle GPIB, Serial ports etc. Booted from ram, loads configuration from the linux pc.
Future plans are to replace MVME162 by a VMIC and suitable hardware interfaces for GPIB, Ethernet, Serial ports etc.
VME V680 clock (TDC)
 Custom TDC for MUSR
VME V680 clock (TDC)
 Custom TDC for MUSR

More Information:

Future Development

It is expected that all MUSR systems will run with VMIC in the near future.
Work is ongoing to replace the MVME162 that runs the CAMP Slow Control system by a VMIC and suitable hardware interfaces for GPIB, Ethernet, Serial ports etc.


The most important part  (as far as the users are concerned) is the User Interface, known as the MUSR Run Control, written in TCL. The MUSR Run Control handles all communications between the users and the Midas DAQ system. Since the users normally interact only with the MUSR Run Control, they do not require any familiarity with Midas in order to run their experiments.

Other software components include the frontend program running on  the VMIC (M15) or PPC (M20/M9B).  In fact, two Midas frontends  to read the data from the hardware are used, one for TD-MUSR and one for I-MUSR,   Only one of these frontend runs at a time (selected by the users, depending whether they want to run a TD or I-MUSR experiment).  Both these frontends share the same Midas Online Data Base (ODB), making switching between experiments simple. The ODB is used to store all parameters needed for the experiments,  including Rig and Mode data.

The TD-MUSR and I-MUSR  programs have the structure of a standard Midas frontend , which handles communication with the Midas DAQ running on the host (linux pc). This communication is over the Ethernet (mostly RPC). The frontend program  controls the  VME scaler, IO board (and clock (TDC) in the case of TD-MUSR).  For TD-MUSR, the frontend reads data from the clock, stores it as histograms, and periodically reads the scaler and sends out the histogram and scaler data to the host, where it is reformatted and stored by the  data archiver (mdarc)  which saves the data onto disk in the same MUD format as before.  When the I-MUSR frontend is selected, it controls the scaler and IO board. It also steps the variable (e.g. DAC) and sends out the data, one point at a time. The data are then formatted into MUD format and stored on disk.

The slow control system software (CAMP)  has been recently (April 2014) updated and rewritten  (by T. Whidden) to run on VMIC as well as its current platforms (MVME162 VxWorks and  Linux-pc). The latest version of the CAMP software is now installed on M15.

The software components most relevent to the users are shown below:
Description program name host
user interface (MUSR run control) musrrc linux pc
TD_MUSR frontend fev680 ppc/VMIC *
I-MUSR frontend
ppc/VMIC *
data archiver mdarc linux pc
client sending additional data for I-MUSR only
linux pc
configures & checks input parameters musr_config linux pc
slow controls camp mvme162/VMIC **

* M15 only (May 2014)
** Future

Improvements with the VMIC-based system

Determine your beamline

The beamline can be one of m15, m9b, m20, [ m9a**, m20d**, dev * ]
*   beamline "dev "  -- is not a real beamline - used only by software developers 
** beamlines "m20d, m9a" in the future

Log In

  Log onto the appropriate linux pc for your beamline:
Beamline  or Username
Desktop pc
midm15x **

M15 counting room

M9B counting room

M20 counting room


DAQ office

** Note that the name of the Desktop pc has changed. It may be renamed to midm15 once the current incarnation of midm15 has been retired.

In the counting room:


  1. Experiments can of course be controlled and accessed over the network. Although this is very convenient, caution must be exercised to avoid problems. For this reason, it is usual to set up the DAQ system in the counting rooms at the consol.
  2. Each beamline account only exists on the appropriate linux pc - e.g. it is not possible to log onto midm9b as m20.

Start the MUSR DAQ

Start the DAQ by typing  (in an xterm window):


Issuing td will start the MUSR Run Control, which will then start any processes that have died (interrogating the user).

If td does not work successfully, issue kill-all then start-all.

Kill All DAQ tasks

If restarting the DAQ after error,  make sure no data acquisition tasks are running by executing the script kill-all .

Type (in an xterm window)


Issuing this command kills all DAQ processes and deletes all windows that were running DAQ processes.

(This does not include any CAMP windows, minicom or other xterms opened by users).

Start All DAQ tasks

Start the data acquisition tasks by typing   (in an xterm window):






** except the frontend if using PPC. The MUSR Run Control will start the frontend on the PPC

The MUSR Run Control

The MUSR Run Control is started by typing in an xterm window :


The MUSR Run Control window (as shown  below) will appear.

Start the Front End (VMIC)...

  VMIC M15    Click here for PPC (M20...)

The frontend for the last-selected  experiment (TD or I-MUSR) will be started automatically by start-allor by the MUSR Run Control program.

musr gui shows
        query start frontend

To Change between I-MUSR and TD-MUSR

On the MUSR Run Control  window, Click on Change. Then select to I-Musr or TD-Musr. Only the one NOT currently running will be offered.

musr run control
      showing query switch to i-musr

The I-MUSR or TD-MUSR Frontend

Depending on whether I-MUSR or TD-MUSR is selected, ONE of the windows shown below will be displayed:

TD-MUSR Frontend window
I-MUSR Frontend window
TD-musr frontend window
I-MUSR frontend window

Select the Run Parameters

The type of run (test/real) may also be changed using the "Change" button.

To Start a Run

Click on the "Run" button, then on "Begin Run" on the MUSR Run Control main page.

Note: you should have previously reviewed the RIG and MODE parameters.

To Stop a Run

Click on the "Run" button, then on "End Run" on the MUSR Run Control main page.

Rebooting the linux computer

The linux computers are very reliable, and it is very rare to need to reboot. 

 Routine problems with the DAQ cannot usually be fixed by rebooting the linux pc.
If start-all followed by kill-all does not fix the problem, please consult a DAQ expert rather than rebooting. 

Start the Front End (PPC)...

PPC Instructions M20,M9B

The frontend (ppc) program is started (or restarted) via a reboot. This may be done as follows:

MUSR Run Control

Frontend (PPC) will not reboot

You will likely see a display from the MUSR Run Control  as follows:


Recovery Procedure:


invisible target 1

To Access the ppc/MVME162 Console Window

The serial (debug) ports on the MVME2306 (Powerpc)  MVME162 (for CAMP) may be displayed on the linux pc.  Both ports are connected to the linux computer's serial ports.
A program called "minicom" is used to display the console window. These can be accessed from the MUSR Run Control:

VMIC frontend window appears then disappears immediately

This usually means there is a VME hardware problem or an error in the frontend code.

On the MUSR Run Control, click Show...Midas Messages to see if there is any relevent message.

If not, start the frontend in an xterm as follows:

    [m15@midm15x] ssh lxm15
    [m15@lxm15]cd ~musrdaq/musr/musr_midas/frontend/m15/

 [m15@lxm15] fev680.exe  for TD-MUSR or [m15@lxm15] femusr.exe  for I-MUSR

Note any error messages and consult a DAQ expert.

VMIC not responding

The VMIC is located in the VME crate. Check that the crate is powered up and try to ping the VMIC.

 Reboot VMIC if not responding.

Reboot the VMIC

VMIC will reboot

The VMIC take a few minutes to respond after a reboot.

If the VMIC is rebooting, wait a few minutes, then ping the VMIC.

Ping the VMIC

Check that the VMIC responds to ping e.g.

    [m15@midm15x ]  ping lxm15

Note that after rebooting, the VMIC will take a few minutes to come up.

If the VMIC does not respond, consult a DAQ expert.

   invisible target 3

To Log out

If using the consol, to log out click the right hand mouse button while cursor is not in any window (i.e. click while cursor is on the (usuallyblue) background).  A menu should appear. Select "logout" by moving the mouse.

invisible target 4

To open an x-term window

Click (left mouse button)  the shell symbol

at the bottom of the screen.