95-8533
2-5
18.2
COMMUNICATION NETWORK
FAULT OPERATION
During normal operation, the Controller is
continuously broadcasting a heartbeat around
the communication loop as shown in Figure
2-2. The Controller broadcasts the heartbeat
in both directions. At the same time, the field
devices are transmitting status information to
the Controller over the communication loop.
Every field device except the network extender
has two LON fault isolation relays. Each relay
is tied to a communication port on the device.
When a field device fails to receive the heartbeat
from the Controller, the device initiates a LON
fault isolation routine. The isolation routine
disconnects one of the communication ports
via one of the LON fault isolation relays.
The device listens for a heartbeat on the
communication port that is connected. If
a heartbeat is not found, the routine then
disconnects the other communication port and
listens for a heartbeat on the connected side.
The process is repeated until either a heartbeat
is located or a LON fault timeout period of two
hours is reached.
The LON fault isolation routine is disabled and
the LON fault isolation relays are closed when
the LON fault timeout period has elapsed.
The LON fault isolation routine will be enabled
when the device again receives a heartbeat.
For a single wiring fault, the field devices with
the fault will isolate the fault by opening LON
fault isolation relays. After the field devices
isolate the wiring fault, communications will
be resumed between the Controller and field
devices. Refer to Figure 2-3.
MULTIPLE WIRING FAULTS
In the event of multiple wiring faults on the LON,
the devices between the faults will continue to
function, but the faults will prevent them from
communicating with the Controller. See Figure
2-4. In this example, nodes 1 to 4 communicate
using one Controller port (path A) and nodes
7 and 8 use the other Controller port (path
B). Nodes 5 and 6 are unable to report to the
Controller because they are isolated by the
two wiring faults. If a device is prevented from
communicating with the Controller, the text
display on the Controller will show the message
“Device Offline.”
IMPORTANT
Since it is impossible to predict where
a network fault might occur or exactly
what effect it will have on actual system
operation, it is important to diagnose
and repair any fault as soon as possible
after it is detected to ensure continuous,
uninterrupted system operation.
SIL2 CAPABLE SYSTEM
The EQP SIL2 capable system uses the
following components:
• EQ3XXX - EQP Controller
• EQ3730 - Enhanced discrete input/output
module
• EQ3710 - Analog input module
• EQ3760ASM - Addressable Smoke & Heat
Module
• X3301 - Multispectrum IR Flame Detector
• PIRECL - Infrared gas detector
Refer to safety system manual (95-8599) for
safety related data.
Figure 2-3—Communication over the LON with a Single
Wiring Fault
Figure 2-4—Communication over LON with Multiple Wiring
Faults
D1851
NODE 1 NODE 8
NODE 3 NODE 6
NODE 2 NODE 7
EQP
CONTROLLER
EAGLE QUANTUM PREMIER
Safety System Controller
Fire Alarm Inhibit Power
SuprHigh Gas
Trouble
Cntrl Flt
Lon FaultLow Gas Ack Silence
Out Inhibit
Eagle Quantum Premier
Time & Date
Cancel Enter Next Previous Reset Acknowledge Silence
DET-TRONICS
®
D1852
NODE 1 NODE 8
NODE 3 NODE 6
NODE 2 NODE 7
NODE 4 NODE 5
PATH A PATH B
WIRING FAULT
EQP
CONTROLLER
EAGLE QUANTUM PREMIER
Safety System Controller
Fire Alarm Inhibit Power
SuprHigh Gas
Trouble
Cntrl Flt
Lon FaultLow Gas Ack Silence
Out Inhibit
Eagle Quantum Premier
Time & Date
Cancel Enter Next Previous Reset Acknowledge Silence
DET-TRONICS
®
D1853
NODE 1 NODE 8
NODE 3 NODE 6
NODE 2 NODE 7
NODE 4 NODE 5
PATH A PATH B
EQP
CONTROLLER
EAGLE QUANTUM PREMIER
Safety System Controller
Fire Alarm Inhibit Power
SuprHigh Gas
Trouble
Cntrl Flt
Lon FaultLow Gas Ack Silence
Out Inhibit
Eagle Quantum Premier
Time & Date
Cancel Enter Next Previous Reset Acknowledge Silence
DET-TRONICS
®
Figure 2-2—Normal Communication over the LON
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