ICENI/AI-04
9.4
Module & Signal Failure Detection
The ICENI/AI-04 module and its input signals are monitored at regular intervals by
the master module to check their health status.
The following faults are detected locally by the ICENI/AI-04 module:
Field Communications
Network
Fault
Type
Fault
Category
Master
Display
ICENI/AI-04
Channel
Status
LED
Measured
Value
Status
Value
sensor resistance
(PT100) < 15 Ohms
(PT200) > 30 Ohms
(PT500) > 75 Ohms
(PT1000) > 150 Ohms
minor
signal fault
measured signal
:
‘warning: low R’
flashing
-200°C
-200°F
1
sensor resistance
(PT100) > 395 Ohms
(PT200) > 790 Ohms
(PT500) > 1975 Ohms
(PT1000) > 3950 Ohms
minor
signal fault
measured signal :
‘warning: high R’
flashing
850°C
850°F
2
sensor
short circuit
major
signal fault
measured signal :
‘fault: s.circuit’
off
-9999°C
-9999°F
3
sensor / cable loop
open circuit
major
signal fault
measured signal :
‘fault: o.circuit’
off
9999°C
9999°F
4
The faults above are non-latching and will self-reset when the failure condition is
removed.
In addition, the following faults are detected by the master module:
Field Communications
Network
Fault
Type
Fault
Category
Master
Display
Master
Fault
Status
Output
Measured
Value
Status
Value
field communications
network attempts to
access data for a
signal channel > 4
network
access
fault
-
-
9999°C
9999°F
7
(channel
unavailable)
ICENI/AI-04 module
stops responding to
master module
module
fault
module status
shown as
flashing red
de-
energises
-
8
(module lost)
The faults above are non-latching and will self-reset when the failure condition is
removed.
With the system operating in a healthy state the following will be observed:
Field Communications
Network
Master
Display
ICENI/AI-04
Channel
Status
LED
Measured
Value
Status
Value
measured value
on
measured
0
Pub_3645
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