Specifications

FX-350 Series Installation and Operation Manual
17
Circuits and Devices
Addressable/Analog Devices
The FX-350 supports up to 3 loops of addressable/analog devices. The device loop can be used to connect up to
60, 126 or 378 analog devices and addressable input or output modules on an unshielded twisted pair (UTP). The
devices must be compatible with the Mircom device protocol.
The loop interface software continuously supervises the devices on its loop against those found during
configuration for the following conditions:
• device missing
• unconfigured device responding
• two or more devices responding to the same address
• wrong device type
A communication or addressing error on a device is reported as a trouble on the associated zone LED if configured.
The addressable loop can be configured for class A or B operation. "T-tapping" is allowed (Refer to device
installation documentation for details). A short or open on the loop will activate the common trouble sequence with a
latching trouble.
Devices on the loop have an optional LED which normally flashes when the device is polled and goes ON steady
when the device is active (alarm for an input device or active for an output device). The flashing of the LED on
polling for sensors can be suppressed during configuration. For input or output modules, the LED always flashes
when polling. The software limits the maximum number of the devices which can have their LED turned ON when
active to fifteen (15).
Certain devices are designed to support an optional external LED, which operates when the LED on the device is
activated. Remote/external LEDs must NOT be used on this system. The panel can provide up to 350mA of current
to the devices on the loop. A maximum line loss of 5 volts is permitted, so the loop distance, wire size, and
maximum number of devices are limited by this constraint. The device currents are as follows:
The devices should be installed using unshielded twisted pair (UTP). The currents above may be used to calculate
the total line drop on the loop, which must not exceed 5 volts worst-case at the last device. The calculations
required to determine the maximum permissible loop wiring distance with various combinations of devices is
relatively complicated, and when isolators are used, includes a consideration of device inrush currents which must
not exceed 20mA for a single isolator. In no case should more that twenty devices be connected to a single isolator.
To simplify the calculation process, please utilize the loop calculator program located on the Mircom website at
http:/www.mircom.com
in order to determine maximum loop lengths, number of devices, and wire sizes etc.
It is also important to note that the device LEDs present a significant extra load on the loop which must be
considered in calculating permissible loop lengths, battery capacities, etc. Please refer to the device Installation
DEVICE CURRENTS (uA)
Device Quiescent Alarm Inrush
Ionization 280 2280 1000
Photoelectric 340 4340 1000
Multi-sensor (Photoelectric/Thermal) 470 3470 1000
Heat 250 2250 1000
Priority Switch Monitor 600 4600 2500
Mini Priority Switch Monitor 600 4600 2800
Single Relay Output 850 4850 3000
Supervised Output 1000 1000 6000
Isolator 35 35 0