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open-ephys / plugin-GUI

Software for processing, recording, and visualizing multichannel electrophysiology data
https://open-ephys.org/gui
GNU General Public License v3.0
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TTL Events Timestamps Error #559

Open mcastelli98 opened 1 year ago

mcastelli98 commented 1 year ago

Hi,

After loading the TTL Events, we noticed that in a few sessions, the timestamps were equal to -1, irrespective of the state being true or false. Moreover, just after the -1s, the values of the upcoming timestamps it's reset (see example below). Sometimes, the timestamps 'reset' happens independently from having a -1 before. Do you know what the -1s mean and what could be causing this and the timestamps reset ?

We are using open-ephys 0.6.0 (and your tools to load the event), and this issue did not seem to occur in previous versions with the same experimental setup.

image

medengineer commented 1 year ago

Hi,

It appears the synchronizer skipped a beat (didn’t detect all the sync signals within that specified period). As a result, a synchronized timestamp couldn't be computed and instead -1 was returned prior to the synchronizer resetting.

Plotting the difference between the timestamps I see a consistent 50 ms difference between TTL ON -> OFF but the OFF -> ON times are inconsistent. Is your synchronization configuration consistent w/ the docs here: https://open-ephys.github.io/gui-docs/Tutorials/Data-Synchronization.html?