Dante Inovonics 541, Installation & User Manual, Page: 39 / 56

— 35 —
Overmod
Alarm: On
‘arms’ the
function in this and all
other alarms to be dis-
cussed. If the alarm is
turned
Off
, there will
be no indicator on the
Now Playing
or
Alarm
Webpages, no closure
at a rear-panel GPO
terminal, nor will the
541 send SMS/text or Email alerts to station personnel or log
the alarm. This applies to all alarms.
Mod (%):
displays the integrated and held-peak value of the total
modulation level for the off-air program being received. This is
the level represented by the green trace on the History Plots /
Modulation / Mod History / Mod Peak screen. The level display here
is ‘grayed-out’ as there is no adjustment that can be made to
the displayed value. Levels displayed in grayed-out meters are
included to help make alarm setup decisions.
Threshold On (%):
is the set point that
Mod Peak
must reach to
trigger an alarm. Moreover, the Mod Peak level must remain at
or above this set point for the number of seconds programmed
with the
Time On (Sec):
slider.
The alarm will reset (clear) when Mod Peak drops to, and re-
mains at or below, the
Threshold Off (%):
setting for the number
of
Time Off (Sec):
seconds.
In the example shown, Mod Peak must reach 105% and stay at or
above that figure for 5 seconds before an alarm is triggered.
Then when
Mod Peak
drops, it must stay below 105% for 20 sec-
onds for the alarm to reset.
In this case we have determined 105% as a ‘drop-dead’ alarm
figure, and a full 20-second blast of overmod as an alarm con-
dition as well. This example alarm setting has no hysteresis,
but provision for this has been included as we’ll see next.
MPX Power
NOTE: Setup of an alarm for MPX power excesses will be of ex-
clusive interest to European broadcasters operating under
ITU-R BS.412-9 restrictions. Setup for this function should be
essentially identical to the preceding illustration for
Overmod
setup, although some deference to the introduction of hystere-
sis may be applicable. Read on.
‘Hysteresis’
Type Alarms
This discussion relates to several alarms with very similar set-
up options. This will pertain to all alarms that have dual
threshold settings:
Threshold On (—):
and
Threshold Off (—):
.