Det-Tronics Eagle Quantum 95-8470-05 Скачать руководство пользователя

Страница: 11 / 128

The bar graph indicates 0 to 100% full scale, which
corresponds to the 4 to 20 ma signal for all gas sensors
except oxygen. The 4 to 20 ma signal from an oxygen
sensor corresponds to 0 to 25% oxygen. Sensor output
(measured in counts per second) is displayed for UV
and UV/IR detectors.

LEDS

Five faceplate LEDs are provided for indicating the
status of the gateway relays. When a relay is reset, the
corresponding LED is also reset.

RELAYS

The communication gateway is provided with five
relays. Four of the relays are general purpose relays.
The fifth relay functions as a fault relay, responding only
to gateway or LON network faults. The relays have form
C contacts rated 5 amperes resistive at 30 vdc.

The specific function of the four general purpose relays
is programmable through Det-Tronics software. The
relays are selectable for latching or non-latching
operation and can be configured for normally energized
or de-energized operation.

CAUTION

When the relays are used as gas alarm outputs in
the non-latching mode, they must be connected to
another device that will perform the latching
function.

RESET PUSHBUTTON

The programmable relays can be reset by pressing the
reset pushbutton or external reset (resetting all latching
relays) or by a command from the EagleVision NT
software (resetting individual relays). The reset function
resets the relay, regardless of the status of the initiating
device. This allows additional events to trigger the
same relay, even though the first device may still be in a
triggering mode.

Automatic Diagnostics

The gateway features self-testing circuitry that
continuously checks for problems that could prevent
proper system response. The gateway performs three
forms of diagnostics: self-diagnostics, LON/SLC
diagnostics, and device diagnostics.

Self-diagnostic tests monitor the condition of the
gateway. LON/SLC diagnostics check for shorts and
opens in the LON/SLC wiring. In the event of a
problem, the fault is annunciated in the gateway status
word and the gateway fault relay is activated.

For device diagnostics, the gateway provides a
watchdog timer for each configured device on the loop.
Each time the device reports to the gateway, the timer
accumulator is reset to zero and the timer starts over. If
a device does not respond before its watchdog timer
expires, the gateway sets the “not communicating” bit in
the status word for that device.

Fault Tolerant Communication

Fault tolerance is provided by constructing the
LON/SLC as a loop that starts and ends at a pair of
network communication ports on the gateway. If a fault
occurs somewhere in the network wiring, fault isolation
circuitry in the communication modules isolates the
problem section of the network. When the gateway
detects the fault, it is immediately annunciated. The
gateway then reconfigures the network so data can be
transmitted to all devices.

This feature minimizes the possibility of a
communication breakdown in the event of an open or
short in the communication loop. A single open or short
on the LON/SLC will not affect system communication
performance. In the event of multiple opens or shorts,
only those detectors between the opens and shorts will
not be able to communicate with the LCU, even though
they will continue to function.

II–4

Table II–2—Status Codes used by Gateway Digital Display (Continued)

Aud

Signal Audible display code

F11

Low Voltage Fault

F12

Low Auxiliary Voltage Fault

F13

Open/Short on Circuit 1

F14

Open/Short on Circuit 2