572
9
Terminal Strip Connections
Feature
Term. #
Description
T
O
S
PEAKER
TB2(10,9)
Connect speakers used for sensing and sound system
usage here. Speakers may be speaker impedance or
constant voltage.
F
ROM
A
MP
TB2(8,7)
Connect amplifier here. Amplifier output may be
speaker impedance or constant voltage.
G
ROUNDS
TB2(6,4,2)
Connect to circuit ground inside the 572.
E
XT
R
ELAY
C
NTRL
TB2(5)
NPN open collector output for driving external relay.
You must supply power for the relay coil. Remember
to connect a diode across the relay coil to absorb the
back EMF generated by the relay coil. The maximum
voltage at this point is 40 V dc at 625 mA.
E
XT
S
ENSE
T
RIG
TB2(3)
Active low input. When option switch D is up,
grounding this terminal forces a sense operation. The
unit remains in sense mode for as long as this terminal
is grounded. The terminal must remain grounded for at
least one second in order to perform sensing.
S
PARE
TB2(1)
Not used, not connected.
G
ROUNDS
TB1(10,6,3)
Connect to circuit ground inside the 572.
L
INE
O
UTPUT
TB1(9,8)
Balanced (differential) output of the 572.
For unbalanced usage, use TB1(9) and TB1(10).
TB1(8) should float.
V
C
TB1(7)
Monitor point for the control voltage for the VCA.
The gain relationship is -159mv/dB. Use this voltage
to verify that the VCA is actually being told to change
the gain or to connect a stereo-slave unit.
P
AGE
I
NPUT
TB1(5,4)
Balanced line-level input for paging signals. Signals at
these terminals cause signals applied to the music
inputs to attenuate (duck). For unbalanced signals,
use TB1(5) for signal and connect TB1(6,4) to ground.
M
USIC
I
NPUT
TB1(2,1)
Balanced line-level for music signals. Normally used
for background music. Signals applied to these
terminals are attenuated (ducked) whenever signals
are present at either of the page inputs.