46131-0598 <90-00018>
P
AGE
3
CIRCUIT DESCRIPTION
F
ig.1 shows the functional schematic for the 46131 Alarm
Processing Unit.
D
ISCRETE
A
LARM
I
NPUTS
All options
The main APU circuit board has 32 discrete alarm inputs that
are optically isolated. Alarms 1-24 each have a single input that
requires a ground to activate the alarm circuitry. Alarms 25-32
each have two inputs, one for negative battery and one for
positive battery.
Options -01 and -21
Alarms 33-64 are on an Expansion Board subassembly that
plugs into the main circuit board. These alarms have a single
input that requires a ground to activate the alarm circuitry.
TBOS A
LARM
I
NPUTS
All options
Eight TBOS interrogator ports can poll TBOS equipment for
alarm information. Each port can poll up to 8 displays of infor-
mation for a total of 64 displays on all eight ports. The data
interface standard on each port is RS-422/485.
Switches allow optional termination of the receive inputs.
C
ONTROL
O
UTPUTS
All options
The main APU circuit board has eight control outputs. Each
output has two pins wired to normally open relay contacts.
Options -01 and -21
An Expansion Board subassembly has an additional eight
control outputs that can be set with switches for normally open
or normally closed contacts.
UPDATED
