USER MANUAL SAGA
Page 33 of 47
Reference Mode/Switch
The Reference Mode event is set by the user in the application software. It shows if
the data is recorded using the Average Reference or Common Reference input. See
6.3 for more information about using reference modes.
When the reference electrode loses contact to the REF input, the amplifier switches
back to Average Reference mode within a few samples, marked in the Reference
switch bit. If the reference channel comes back in range, the reference mode will
NOT switch back again. This prevents data to be unusable in case the reference
electrode becomes detached, but still makes contact to the skin. This could lead to
switching references throughout the total recording, which is undesirable.
During post-processing of the data, it is important to always monitor the Reference
Mode event, as it directly influences the measurement reference.
Trigger inputs
The digital input of the Data Recorder (marked DIGI) can be used to record a event
trigger from an external source. The digital input is an isolated input so a TTL level
signal can be used to mark specific timepoints. The trigger is sample synchronous
to all the other data.
Battery low
The Data Recorder runs on one or two batteries. In case two batteries are used, they
are drained on an ‘equal level’ basis. This means that the battery with the highest
charge level is drained until they reach an equal level (in case of using batteries with
unequal battery charge levels).
When the battery charge becomes low, the Data Recorder logs an event, marking
which of the batteries is low. One or both batteries should be replaced or recharged.
When the batteries are empty, the Data Recorder logs a ‘battery empty’ event. The
Data Recorder will close any running data acquisition session and power down.
