Installation and programming manual
Diagnostics and fault solutions
59
Chapter 17
Diagnostics and fault solutions
Danger:
Only authorized operators (Level 2 or 3) may search for, and correct faults.
17.1
“Open I/O” fault
The panel is unable to find the EOL resistor on the supervised input/output terminals. The next line
indicates the specific terminals (NAC, on a module connected to the loop etc.).
Check the EOL resistor connection on the last device. Using a tester check that the resistor has not burnt
out.
17.2
“Shorted I/O” fault
A short-circuit has been detected on the input/output terminals. The next line indicates the specific terminals
(NAC, on a module connected to the loop etc.). Check the device connections and cable sections.
17.3
Loop fault
17.4
Testing the Loop
For the distinction of the internal LEDs ([A], [B] or [C]) refer to paragraph
5.2
.
17.4.1 Testing the Loop status LEDs
Verify that the loop transmission LED [B] or [C] that blinks matches the loop type setting. In the event of
mismatch, check the loop parameter settings.
Message on display
Cause
Remedy
Short-circuit
on A
A short-circuit has been detected
on the wiring section between
the “Loop - O” terminals and the
first isolator on the loop.
Check the connections and integrity of the wiring on the section
concerned.
Short-circuit
on R
(for 4-wire loops
only).
A short-circuit has been detected
on the wiring section between
the “Loop - I” terminals and their
nearest isolator on the loop.
Check the connections and integrity of the wiring on the section
concerned.
Loop Open
(for 4-wire loops
only).
No loop continuity
between the “Loop-O”
and “Loop-I”
terminals.
One or more open isolators on
the line.
Check all the isolators on the loop: the LED of at least one of the
isolators will indicate “isolated” status. Once you have found the open
isolator, check the connections and integrity of the wiring on the cable
section between the open isolator and the successive one.
Interrupted cable
Disconnect the "Loop-I" terminals of the panel; search the loop until
you find the last device on the line in working order. To check whether
a device is working or not, access the Main menu from the panel and
select “
Maintenance, Test zone
”. This menu will allow you to
turn the various device LEDs On and Off (refer also to
Chapter 16 -
Maintenance
). Once you have found the last device on the line in
working order, check the connections and integrity of the wiring in the
adjacent cable section.
The number of devices found by
the panel is less than expected.
Using the “
Maintenance, Test zone
” menu, identify the
devices that are not recognized (refer also to
Chapter 16 -
Maintenance
). Check the wiring of the devices concerned and their
respective addresses.
Duplicated address: means the
same address has been assigned
to two devices.
Using the “
Maintenance, Test zone
” menu
:
turn On the LED
of the device with the duplicated address; find the loop devices with
the duplicated address and assign them new addresses. Refer also to
Chapter 16 - Maintenance
.
