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Restart Acquisition

Problem:
- SQUID controller (SQC), Signal Acquisition Module (SAM), System Controller (SCC) dropped out during acquisition.
- SQC, SAM, SCC previously disconnected.
Solution:
- SCC reset (Main Electronics Cabinet, SCC card, Reset button).
- Restart Acquisition Programs (Neuromag applications, Maintenance folder).
- Download the latest Tuning file with Tuner (Acquisition > Tools > Tuner).
If nothing else helps
- Switch off/on the power in the Main Electronics Cabinet (by MEG Support!).
- Restart Acquisition Programs (Neuromag applications, Maintenance folder).
- Download the latest Tuning file with Tuner (Acquisition > Tools > Tuner).

Resetting the electronics

The MEGIN TRIUX has four different Digital Signal Processing (DSP) electronics boards:

  • SQUID controller (SQC) board, used for MEG channels, HPI and Internal Active Shielding.
  • Signal acquisition module (SAM) board, used for bioamplifiers, EEG, and analog signal input.
  • System controller (SCC) board, a master board for the main electronics.
  • Front end controller (FEC) board, used for controlling the preamplifiers.

Each main electronics board has a recessed Reset button on its front panel.
If the board becomes locked up (e.g. showing a red Fail LED, or it is reported by the acquisition sofware (megacq) as been dropped from acquisition) press the Reset button.
Boot-up of the boards starts automatically.
Wait until the board shows a steady green Run LED and the Fail LED is off.
Boot-up takes about 30—60 seconds.
If the bootup fails, open the back door of the main electronics cabinet and check the indicator LEDs of individual power supplies.

Note

If several boards fail simultaneously, all boards can be reset simultaneously by pressing the Reset button of the System Controller Card [SCC] which, in our installation, is located 5th slot from the right in the middle rack in the electronics cabinet. Most MEG sites detail this slot with a label/arrow.

After resetting the boards, run Restart Acquisition Programs by double-clicking its icon in the Maintenance toolbox on the acquisition workstation. See the specific RAP page for the full procedure.

The SCC and FEC boards also have status LEDs for the optical links of the stimulus trigger interface units and MEG and Bio/EEG preamplifiers. The Link LEDs should be lit green after resetting the boards.

Note

Each time the MEG front-end electronics are reset, or powered off/on, they must be initialized by invoking the Restart Acquisition Programs, a RAP, and the correct/up-to-date Tuning File must be reloaded.

Restarting the software

When to restart

The data acquisition may under some circumstances either stop prematurely or freeze with the following symptoms:

  • Megacq becomes non-responsive for a long time. When windows covering megacq are moved, the exposed areas are not repainted.
  • When megacq is started it fails to contact the data server.

The most common reasons for this are networking problems.
Recover the system by restarting the acquisition software modules.

If the front-end DSP boards hang up, a complete power cycle is not normally required. It is enough to ...

  • Stop/Close the Acquisition program (megacq).
  • Reset the DPS boards (See the Resetting the electronics section above).
  • Perform a RAP
  • Restart the Acquisition program again.

The DSP boards are reset by pressing the Reset button on the SCC board panel in the electronics cabinet and waiting until all DSP boards boot-up to green Run-status.
See the Resetting the electronics section above.

Procedure to restart the software (perform a RAP)

  1. Stop/Close the Acquisition program (megacq).
  2. Open the Maintenance folder under the Neuromag folder in the Desktop’s Applications menu to see the available actions.
  3. Select the Restart Acquisition Programs icon ("RAP").
  4. Confirm that you really want to proceed by answering "Y" to the question appearing in the Restart Acquisition Programs terminal window.
  5. Observe the messages in the window during the restarting.
    • Should the restart operation fail, verify all physical power and data connections, as well as network connections, are working. Then ...
    • Close the terminal window, and try from point #2 again. If successful, then...
  6. Wait until the message...
    Restart complete. Press <Enter> to close the window
    ...appears and press Enter on the keyboard.
  7. If you had collected data and megacq ceased to work after you pressed Stop, you can rescue your data by double-clicking the Rescue Data icon in the Maintenance folder.
    • If there is some data to be saved, you will first see a dialog to confirm that you would really like to proceed. Thereafter, a standard megacq saving dialog will appear. The rescued data will be saved under the project directory called unknown if the real project name could not be retrieved.
  8. Restart megacq by selecting the Acquisition icon in the Neuromag folder.

Loading a Tuning File

Procedure to load a tuning file, to check sensor noise levels, and to make sure the correct file is loaded after a Console reboot/MEG front-end reset or power off/on.

  1. Start the Acquisition program (megacq) on the DACQ Console.
  2. Select Tools > Tuner from the menu bar at the top of the Acquisition window.
  3. Select File > Load tunings from the menu bar. A dialog window will pop up...

    OK to load state file /neuro/dacq/tunings/tnp/He_90.tnp

  4. If this is the file wanted, click OK. Otherwise, click Load other to pop up an ordinary file selection box and browse for the file required. Click OK once the required file to be loaded has been found.
  5. Click on the Measure noise button, to start a noise check.
  6. Look at the generated "Manhatten Skyline", warm any sensors that are reaching atypical levels...
    • CTRL + left click on the noisy sensor "building"
    • Commands > Heat sensor, trace should reduce in height/noise level reduce
    • CTRL + left click to return to the "all sensor" view
    • Once happy, click Stop measurement, followed by Stop Collector
  7. To exit Tuner, select File > Exit. A dialog window will pop up, select "Yes"

Note

He_90.tnp is the default filename expected by megacq when the software is started. After a completed tuning session, ensure that the new tuning file is saved under this name. A backup copy can then be made by selecting File > Save Tunings > Save elsewhere and chosing a different filename e.g. date of tuning/gantry position.