Specifications

Document Ref: Dis4app.doc / Rev 0 25.07.00 Page 12 of 22 Originator MC Checked__AC_
3.5 Use of Auxiliary Inputs
Auxiliary inputs are provided to allow remote operation of the following functions:
• Fault
• Evacuate
• Silence
• Reset
Each input circuit is fully monitored for open and short circuit faults. To activate an input a
680 ohm resistor should be connected across the input circuit by a normally open switch
contact. Two switches are shown in Figure 1 although there is no limit to the number of
switches.
680R
680R
SWI TCH SWI TCH
END OF LINE
3k9
INPUT CI RCUI T
INPUT CI RCUI T
Figure 1 – Input circuit configuration
3.6 Alarm circuits
The Discovery panel has two alarm circuits, each rated at 1A. The circuits are reverse polarity
monitored for open and short circuit faults. To allow monitoring all devices must be polarised
To prevent damage to the control panel bells must also be suppressed a bell fit diodes as
shown in Figure 2. The circuit must be terminated with a 3k9 end of line resistor.
END OF LINE
3k9
POLARI SI NG
DIODE (E.G. 1N4002S)
BELL SOUNDER
SUPPRESSI ON
DIODE (E.G. 1N4002S)
ALARM CIRCUI T +
ALARM CIRCUI T -
Figure 2 – Alarm circuit configuration