The magnetic oitest is performed by placing a magnet
by the marked location (mag oi) on the outside of the
detector. The manual oitest is accomplished by
connecting the oilead (terminal 22) to power supply
minus via an external switch. The magnet or switch must
be held in place for a minimum of 6 seconds to
complete the test. Either of these test methods activates
the calibrated IR emitter. If the resulting signal meets
the test criteria, indicating that greater than half of the
detection range remains, the Alarm relay changes state,
the indicating LED changes to red, and the 4-20 mA
current output goes to 20 mA. This condition remains
until the magnet is removed or the switch is released. If
the alarm relay is configured for non-latching operation,
it will change states and the red LED will turn to green.
If the unit has latching relays, they can be reset by
removing input power (0.1 second minimum) or by
momentarily applying the magnet or manual oiswitch.
If less than half of the detection range remains, no alarm
is produced and a fault is generated. The fault
indication can be reset by momentarily applying the
magnet or manual oiswitch.
NOTE
Refer to the Appendix for FM verification of Det-
Tronics’ patented Optical Integrity oi™ function.
COMMUNICATION
The X9800 is furnished with an RS-485 interface for
communicating detector status and other information
with external devices. The RS-485 uses MODBUS
protocol, with devices configured as slaves.
DATA LOGGING / EVENT MONITORING
Data logging for event monitoring capability is also
provided. The detector can log up to 1500 events (up
to 1000 general and 500 alarm events). Status
conditions such as normal, power down, general and oi
faults, pre-alarm, fire alarm, time and temperature are
recorded. Each event is time and date stamped, along
with the temperature and input voltage. Event data is
stored in non-volatile memory when the event becomes
active, and again when the status changes. Data is
accessible using the RS-485 port.
INTEGRAL WIRING COMPARTMENT
All external wiring to the device is connected within the
integral junction box. The screw terminals accept wiring
from 12 to 22 AWG. The detector is furnished with four
conduit entries, with either 3/4 inch NPT or 25 mm
threads.
SIGNAL PROCESSING OPTIONS
The X9800 features signal processing options. These
options
determine the type of logic that the detector will
use for processing fire signals
to customize the X9800 to
the application. Two signal processing options are
available for the X9800:
–TDSA enabled
–Both TDSA and Quick Fire enabled (either initiates
fire alarm).
Time Domain Signal Analysis (TDSA)
The TDSA signal processing technique analyzes the
input signal in real time, requiring the IR signal to flicker
randomly in order to recognize it as a fire condition.
Using TDSA signal processing, the X9800 ignores
regularly chopped blackbody sources (occurring in
areas where moving conveyors and hot objects in
proximity to one another result in a regularly chopped IR
signal), because it looks for a less uniform signal.
However, in the presence of a regularly chopped signal,
the unit is more susceptible to false alarms due to
sporadic IR that functions as a trigger when occurring in
conjunction with the regularly chopped signal.
Quick Fire (High Speed)
The Quick Fire (High Speed) feature can be used in
conjunction with the TDSA signal processing method.
This method overrides TDSA requirements in the event
of an intense signal. When Quick Fire is activated, the
detector is capable of responding to an intense fire
signal in less than 30 milliseconds (0.030 seconds).
Using the Quick Fire feature in conjunction with TDSA
signal processing allows the detector to provide a high
speed response to a large, non-flickering fire (such as
in high pressure gas applications) while maintaining an
ability to respond to smaller fires.
395-85541.1
