Fault
Responses
Causes
Voltage supply of the
main module is higher
than the operating
range
•
Safety controller switches to the
critical error status
•
Internal error
module status bit = 0
•
Fault in the voltage supply
•
Short-circuit to other volt‐
age-carrying line
Table 10: Faults in the safety capable inputs (I)
Fault
Responses
Causes
Electro-mechanical
switch/safety switch
(EMSS), safety sen‐
sors with test input,
Flexi Loop: safety
capable input is Low
instead of High
•
Process data bit of the affected
input = 0
•
Short-circuit to another line
e.g., GND
•
Error in the sensor
•
Line break
Electro-mechanical
switch/safety switch
(EMSS), safety sen‐
sors with test input,
Flexi Loop: test
pulses from the asso‐
ciated test output
X are not detected
correctly (short-circuit
detection)
•
Process data bit of the affected
input = 0
•
Status Ix
process data status bit =
0
•
Module status bit of the affected
Status Ix
input = 0
•
Short-circuit to other volt‐
age-carrying line
•
Error in the sensor (for exter‐
nally tested sensors)
Dual-channel elec‐
tro-mechanical safety
switch (EMSS), safety
sensors with moni‐
tored semiconductor
outputs (OSSD): equiv‐
alent/complementary
safety capable inputs
exhibit different/the
same values.
•
Process data bit of the affected
input = 0
•
Status Ix, ly dual-channel evaluation
process data status bit = 0
•
Module status bit of the affected
Status Ix, ly dual-channel evaluation
input = 0
•
Short-circuit to another line
e.g., GND
•
Error in the sensor
•
Line break
•
Discrepancy time
•
Sequence error
Safety pressure mats:
safety capable input
is Low instead of test
pulse signal from the
associated test output
X
•
Process data bit of the affected
input pair = 0
•
Status Ix
process data status bit =
0
•
Module status bit of the affected
Status Ix
input = 0
•
Line break
Test output
→
sensor
•
Line break
Sensor
→
safety capable
input
Safety pressure mats:
safety capable input is
High instead of test
pulse signal from the
associated test output
X
•
Process data bit of the affected
input = 0
•
Status Ix, ly dual-channel evaluation
process data status bit = 0
•
Module status bit of the affected
Status Ix, ly dual-channel evaluation
input = 0
•
Short-circuit to other volt‐
age-carrying line
Internal error detected
in input evaluation
•
Safety controller switches to the
critical error status
•
Internal error
module status bit = 0
•
Internal device error
10
TROUBLESHOOTING
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O P E R A T I N G I N S T R U C T I O N S | Flexi IO XTDO1
8024583/2020-11-10 | SICK
Subject to change without notice