Bosch Plena - Page 33

Bosch Security Systems | 2006-06 | 9922 141 10377 en
Plena Voice Alarm System | Installation and User Instructions | Equipment en | 33
Internally, the positive override pins (Z+) are all
connected to either the NC or the NO contact of the
Volume Override output (see figure 5.10). The negative
override pins (Z-) are all connected to earth.
Normally, when there are no active calls, the Z+ pins
are internally connected to the NC contact of the
Volume Override. At the moment a call is started in a
zone, the Z+ pin of the zone is internally connected to
the NO contact of the Volume Override. So, the NC and
the NO contacts determine which voltage is supplied to
the positive pins of the override outputs (Z+).
figure 5.10: Volume override contacts
Z1
+
_
Z2
+
_
Z3
+
_
Z4
+
_
Z5
+
_
Z6
+
_
NO NC