25
The automatic recording mode
In the automatic recording mode, it is possible to make unattended, automatic recordings
using a level-triggering mechanism. The automatic recording mode is selected in the settings
menu.
The signal level above which the system is triggered can be changed each time a new
recording session is initiated (the MIC key is pressed). The level can be set to one of eight
values. After selecting the desired level, confirm this by pressing the ENTER key. Level 7
will require the highest signal level in order to trigger the system, with correspondingly lower
signal levels for triggering levels from 6 and down. Level 0 will cause the system to trigger
even in the absence of an input signal.
When the automatic recording mode is selected in the settings menu, the following triggering
parameters should also be selected.
T = number of times the signal has to exceed the trigger threshold (“the number of triggering
pulses”) in order to trigger the recording system.
P = the minimum spacing in milliseconds between two consecutive triggering pulses. If two
pulses are closer than this value, the second pulse will not be counted.
W = the count window, i.e. the time interval in tens of milliseconds within which the T
pulses have to be counted in order for the recording system to be triggered. E.g., if a value of
3 is entered, the system will count pulses over an interval of 3 x 10 = 30 ms.
F = the minimum spacing in tens of seconds of two consecutive files. E.g., if a value of 3 is
entered, the system will wait for 3 x 10 = 30 s after a recording is finished until it makes the
system ready to record the next signal.
The P and F parameters, can take values between 0 and 9, while the allowed values for the T
and W parameters are between 1 and 9. It should be noted, however, that some combinations
are not allowed. For instance, if T = 4 and P = 8 at least 4 pulses within 24 (3 x 8) ms are
required to trigger the recording system. In that case, setting the W parameter to a value of 2
(20 ms) or lower, means that the system would never be triggered. Such combinations are
automatically eliminated as the parameters are entered.
After pressing MIC, selecting the desired trigger level and confirming this by pressing
ENTER, the detector enters the automatic recording mode. When ARMED is shown on the
display and the ARMED LED is lit, the detector awaits a trigger (the triggering conditions
according to the chosen parameters are met). Upon receiving a trigger, a sound file is created
with the length determined by the chosen values for PRE and POST. After finishing each
recording, the detector waits for F x 10 seconds and then becomes armed again. To exit the
automatic recording mode, press MIC while the display shows “WAITING”. It is also
possible to exit the ARMED condition by pressing the MIC key.
The figure below illustrates the Automatic recording mode.
