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Noisy Channels / Head Localization Problems Notification 6-15-18

Since our electronics failure, we have been experiencing issues with ACQ.

• Upon starting the Acquisition Manager, occasionally there may be:

1) extremely noisy channels, and/or
2) Head Localization results will register outside of tolerances and/or will not complete. 

We believe that this is related to files which controls the calibration of the individual channels. CTF has been working on this issue with us and hopes to have the system significantly more stable by the end of the week.

• If you do observe issues, restarting ACQ is usually enough to eliminate the problem. However, you may have to restart ACQ several times.

• Additionally, you can delete the noisy channel from acquisition.

Thanks for your patience as we work to solve these issues!

Procedure for restarting the rack

There are times that the MEG electronics rack needs to be rebooted.

  • If the Acq starts with some noisy channels, usually restarting the Acq will make the noise go away, if not reboot.
  • If the HLU does not work, you must reboot the entire rack.

There are two important power buttons

  • The button on the DSQ 3500 Electronics Control Console (EC Console) with the ring of light controls the power to the electronics rack. This light changes colors when the rack is powered up.
  • The Head Localization Unit (HLU) power box, on the top of the new rack, has a button with a light within it. Press this button to turn on and off the HLU unit.

To restart (reboot) the electronics rack:

  1. First you must make sure the you have closed ACQ.
  2. Then power off the rack. Press the button on the EC console.
  3. Next you must power off the HLU box which is located on top of the new rack. Press it to turn off the HLU.
  4. Return to the console and power the rack back on.
  5. Wait about 10 seconds.
  6. Next, turn the HLU box back on.
  7. Now you can launch Acq.
*Please contact MEG staff for assistance if you are unable to resolve problem(s).

Procedure for Resetting the JOYSTICK /FORP CONTROLLER

To SET / RE-set the FORP:

  1. Press the knob (shaft) on the right.
  2. The Display will read: “Change Modes?” Rotate to select and press the knob.
  3. Select: “Autoconfigure” (at the top). Press the knob.
  4. Select: “Legacy Handheld” (a ways down). Press the knob.
  5. Select: “USB” then press the knob.
  6. Select: “USB Key 12345” then press the knob.

To SET / RE-set the JOYSTICK:

  1. Press the knob (shaft) on the right.
  2. The Display will read: “Change Modes?” Rotate to select and press the knob.
  3. Select: “Autoconfigure” (at the top). Press the knob.
  4. Select: “HID JOYSTICK”. Press the knob.
  5. Select: “HID Key 12345” then press the knob.


Segmentation violation when starting Matlab R2017b and later under Fedora 28

Matlab segmentation violation under Fedora 28

This error occurs when your computer cannot load a certain font display library through MATLAB. To resolve the issue, please navigate to MATLAB R2017b/R2018a installation location in your system and remove the “” library file shipped with MATLAB R2017b, so that MATLAB will use the system version of that library:

  • The freetype libraries are installed in _matlabroot_/bin/glnxa64/.

Following are the commands to execute in a linux shell to perform the above mentioned operation: (You may need root privilege)

cd /opt/matlab (or wherever you may have installed MATLAB)
cd bin/glnxa64
mkdir exclude
mv libfreetype* exclude/

Now, please start MATLAB normally.