Scanner trigger problem

Hardware General
1

Dear all,

We recently got a Lumina 3G+ controller to use in an fMRI study, but we are having problems to receive the scanner triggers. The Lumina is connected to a 3T Siemens MRI scanner and to a MacBook Pro (macOS Big Sur, 11.5.1), and is set to Keyboard mode using ASCII (firmware 2.2.8). The problem is that sometimes the trigger is received and sometimes not. This seems completely random, and in any case the trigger light (on Lumina) never turns on. We tried a Lumina controller from other research group that has an older firmware (version 2.0) and this does not occur, i.e., every trigger is received and everything runs normally. Any idea on what might be happening?

Any feedback is appreciated.

Thanks in advance,
Marta

2

Please download Xidon and run it. When Xidon detects the controller:

  • Click on the Device menu and choose Lumina 3G Options; a dialog opens.

  • Click on the middle tab Signal Options.

  • In the list of signals, select “Scanner Trigger”.

  • Make sure that the Hold on period and Hold off period are both set to 0ms.

  • Make sure that the Enable single shot feature option is turned off.

  • Click on OK and exit Xidon.

Does this solve the problem?

3

Thank you for your suggestion but we have already try that and the problem remained.

One aspect that may be important is that this problem only arose when we updated the firmware from the original version to version 2.2.6 (later we updated the firmware to the version 2.2.8 and the problem remained). Any ideas?

4

We are looking into it. Please allow us some time, it might be a firmware bug.

6

We have found and fixed the bug in the firmware. It turns out that it was always there, but did not manifest itself until we added some of the signal filtering options, e.g. to filter out scanner slice triggers.

Firmware version 2.2.9 is now available.