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14
3.2.3 Setting the Digital Output Jumpers
Each digital output has an associated jumper to define its
operation when power is interrupted. This puts the AC4
in a fail-safe mode and ensures proper functioning when
the board has no power.
The AC4 comes from the factory with all digital output
jumpers in the OFF position (normally open). The jumper
setting for each digital output can be changed to ON (nor-
mally closed). The settings are shown in Table 5.
To change the output jumper setting:
1. Find the respective loss-of-power jumper on the
circuit board, as shown above. See Table 1 - Controller board components for more
information.
2. Decide whether your configuration requires the jumper to be OFF or ON.
3. Set the jumper as needed:
• Set the jumper to OFF by placing the loss-of-power jumper on the middle and top pins.
• Set the jumper to ON by placing the black jumper on the middle and bottom pins.
3.3 Connecting Common Alarm Outputs
The common alarm relay, found in the top right corner of the
AC4, permits the user to connect auxiliary notification equip-
ment, such as lights, horns and sirens, to the AC4. To determine
the proper wire size, see Table 4 - Wiring specifications.
There are two connectors for the common alarm output. However,
the connectors are not individual relay outputs. The connectors
should be treated as a double-pole, double-throw (DPDT) relay.
The common alarm relay is energized whenever an alarm occurs.
To connect an output:
1. Turn OFF electrical power to the AC4.
2. If necessary, remove a conduit knockout to permit wire entry into the AC4 enclosure.
3. Bring the wire(s) into the AC4 enclosure through a conduit knockout or access slot.
4. Loosen the appropriate screw and slip the stripped end of the wire into the terminal block.
5. Tighten the screw until it holds the wire snugly.
3.4 RS232 Connector
The AC4’s Service Terminal Interface offers full con-
figuration and monitoring capability via the RS232
port (see A.2 - Connecting to the Service Termi-
nal Interface).
The RS232 port requires a null modem cable. Connect
one end of the cable to the AC4’s RS232 port, shown
at right, and the other end to the COM1 port of a lap-
top computer or video terminal.
Table 5 Digital output jumper settings
Setting
Output status
(power loss)
OFF Normally open
ON Normally closed
Digital output jumpers (four)
Common alarm outputs
Serial
interface
connector
(RS232/
EIA574)