# Question about digital trigger channel for Neuromag-122 data
**URL:** https://mne.discourse.group/t/question-about-digital-trigger-channel-for-neuromag-122-data/82
**Category:** Mailing List Archive (read-only)
**Tags:** list-archive
**Created:** [January 4, 2009, 1:58pm UTC](https://mne.discourse.group/t/question-about-digital-trigger-channel-for-neuromag-122-data/82 "2009-01-04T13:58:34Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@system](https://mne.discourse.group/u/system)
#### Post date: [January 4, 2009, 1:58pm UTC](https://mne.discourse.group/t/question-about-digital-trigger-channel-for-neuromag-122-data/82/1 "2009-01-04T13:58:34Z")
I am looking for help on how to set up the digital trigger channel
correctly for analyzing Neuromag-122 raw data using MNE.
I did trial-and-error in changing STI 001 ... 006, 015, 016, to STI 014
one at a time, but each time, the event numbers were incorrect (over
20,000 events were found) in doing mne\_process\_raw. mne\_fix\_stim14 did
not help remove the problem.
I tried to senenv for trigger channel to be one of the STI channels in
the raw data, but the events were not detected at all.
Your advice is greatly appreciated.
~ Yang
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### Author:  [@system](https://mne.discourse.group/u/system)
#### Post date: [January 4, 2009, 3:44pm UTC](https://mne.discourse.group/t/question-about-digital-trigger-channel-for-neuromag-122-data/82/2 "2009-01-04T15:44:18Z")
Hi Yang,
> I am looking for help on how to set up the digital trigger channel
> correctly for analyzing Neuromag-122 raw data using MNE.
> I did trial-and-error in changing STI 001 ... 006, 015, 016, to STI
> 014 one at a time, but each time, the event numbers were incorrect
> (over 20,000 events were found) in doing mne\_process\_raw.
> mne\_fix\_stim14 did not help remove the problem.
> I tried to senenv for trigger channel to be one of the STI channels
> in the raw data, but the events were not detected at all.
>
> Your advice is greatly appreciated.
>
> ~ Yang
On Neuromag-122 systems the digital trigger channel does not exists
but rather there are separate channels (STI 001 ... STI 006) which
together give the trigger information. Furthermore, these channels are
really analog channels and must be thresholded to detect the triggers
correctly. This is the reason of getting 20,000 events when you
experimented with different channels.
Fortunately, there is already a solution (a little bit cumbersome).
Download the newest MNE Matlab toolbox (MNE-dist-matlab-2.6-
beta-081102134414.tar.gz) from our download website. This new version
contains a function called mne\_make\_combined\_event\_file which will
combine STI 001...STI 006 and creates both a text and binary format
event files. Once the binary event file (\-eve.fif) is in the
same directory as your raw data file, it is consulted for trigger
events and everything should work correctly (the --digtrig setting is
irrelevant).
I hope this helps.
- Matti