Pittway NOTIFIER AFM-16AT, Руководство по установке

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Document 15048 Rev. D1 07/16/97 P/N 15048:D1
5
Fire Alarm
Control Panel
Wiring
Communication between the control panel and the AFM is accomplished over a two-wire
power-limited EIA-485 serial interface (formerly referred to as RS-485). This communica-
tion, to include the wiring, is supervised by the control panel's CPU. Loss of communication
results in "System Trouble" and "Module Failure" indications at the CPU. Power for the AFM
must be power-limited and is provided via a separate power loop from the control panel which
is inherently supervised (loss of power also results in a communication failure at the control
panel). No End-Of-Line Resistor needs to be installed because the EIA-485 circuit is
internally terminated on the annunciator.
Wiring Specifications
The EIA-485 circuit cannot be T-Tapped; it must be wired in a continuous fashion from the
control panel to the AFM. The maximum wiring distance between the panel and annunciator
is 6000 feet. The wiring size should be a 18 AWG to 14 AWG twisted-pair
cable having a Characteristic Impedance of approxi-
mately 120 ohms. Limit the total wire resistance to 100
ohms on the EIA-485 circuit, and to 10 ohms on the power
run to the annunciator. Do not run cable adjacent to, or in the same
conduit as, 120 volts AC service, noisy electrical circuits that are powering mechanical bells
or horns, audio circuits above 25 volts
RMS
, motor control circuits, or SCR power circuits.
Twisted-shielded wiring should be used for EIA-485 circuits that are not contained entirely
in conduit.
Functions
The fire alarm control panel automatically assigns annunciator points to the modules directly
to the right of the CPU and outward. Therefore, when installing the system modules, Initiating
Zone Modules (IZ-4, IZ-8, or IZM-8) should be installed in ribbon cable positions immediately
next to the CPU (and outward) to permit full annunciation of initiating circuits.
AFM
Annunciator
Two-wire EIA-485
Circuit
(Maximum of 6000 feet )
power-limited
Power for AFM
(18 to 14 AWG )
power-limited
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