33
Failure Modes
Appendix D
Instruction book, IQAN-XA2
Appendix D
Failure Modes
The following tables contain information about the different possible failures that could occur
for each module subsystem. In most cases when an error is detected, a message will be
presented on the master display together with an error code on the module. In some cases, the
module will turn off or at least shut down the outputs, to increase safety.
Failure modes for VREF
Failure modes for CAN interface
Failure mode
Effect
1
+VREF Open
VIN out of range, will create a VIN error =>
VIN=Predefined error value.
a
a.
Measure is controlled by CAN master and application as a result from the CAN error
message. Turning outputs off is controlled by CAN master unit and therefore delayed
maximum 2 bus cycles.
2
-VREF Open
VIN out of range, will create a VIN error =>
VIN=Predefined error value.
a
3
+VREF
S
hort-circuit to -VREF
VREF error => VIN out of range, will create a VIN
error => VIN=Predefined error value.
a
4 +VREF
S
hort-circuited to +BAT
VREF error => VIN out of range, will create a VIN
error => VIN=Predefined error value.
a
5 +VREF
S
hort-circuited to -BAT
VREF error => VIN out of range, will create a VIN
error => VIN=Predefined error value.
a
6 -VREF
S
hort-circuited to +BAT
External fuse (if <7.5A) on +BAT blows.
7 -VREF
S
hort-circuited to -BAT
Not detected.
Failure mode
Effect
1
CAN-H to -BAT
No CAN communication. All output turned off.
2
CAN-L to -BAT
No CAN communication. All output turned off.
3
CAN-H to +BAT
No CAN communication. All output turned off.
4
CAN-L to +BAT
No CAN communication. All output turned off.
5
CAN-L open circuit
No CAN communication. All output turned off.
6
CAN-H open circuit
No CAN communication. All output turned off.
7
CAN-L to CAN-H
No CAN communication. All output turned off.
8
CAN-termination failure, termina-
tion on
No effect
9
CAN-termination failure, termina-
tion off
Dependent on CAN size and number of CAN nodes.
