Siemens SIMATIC S7 - Page 127

Fail-Safe signal module (SM) diagnostics
6.2 Fault diagnostics
S7-1200 Functional Safety Manual
Manual, 02/2015, A5E03470344-AA
127
Event ID
Diagnostic mes-
sage
Fail-safe signal
module
Description
Possible causes
Corrective measures
1
0x0302 Discrepancy fail-
ure,
channel state 1/0
SM 1226 F-DI
16 x 24 VDC
External discrepancy
failure: Channel state
1/0 with 1oo2 equiva-
lent configuration
•
Short-circuit
• Sensor mechan-
ical activation or
alignment out of
tolerance
sors are mounted and
aligned to be activated
together.
0x0303 Discrepancy fail-
ure,
channel state 1/1
SM 1226 F-DI
16 x 24 VDC
External discrepancy
failure: Channel state
1/1 with 1oo2 non-
equivalent configura-
tion
0x0306 Internal sensor
supply
short-circuit
to P
SM 1226 F-DI
16 x 24 VDC
SM provided sensor
supply voltage short-
ed to P
Sensor supply
shorted to P
• Eliminate the short-
circuit.
• Once the fault is
eliminated, the power
must
be switched off and on.
Short-circuit test
duration configured
too short
Increase short-circuit test
duration.
Failed sensor supply
Replace the fail-safe SM.
0x0307 Overload or inter-
nal sensor supply
shorted to ground
SM 1226 F-DI
16 x 24 VDC
Internal sensor sup-
ply
voltage shorted to M,
ground, or excessive
load on sensor sup-
ply
Short-circuit
• Eliminate the short-
circuit.
• Once the fault has been
eliminated, the power
must
be switched off and on.
Excessive load on
sensor supply
Reduce load on sensor
supply.
Failed sensor supply
Replace the fail-safe SM.
0x030B Channel failure
acknowledgement
All Channel configured
for manual acknowl-
edgement is ready to
reintegrate
Manual acknowl-
edgement required
Manually acknowledge
correction of channel fault
so that reintegration can
occur.
0x0311 Frequency too
high
SM 1226 F-DQ
4 x 24 VDC
SM 1226 F-DQ
2 x Relay
Switching frequency
exceeded; readback
not in time
Process value from
safety program
changing too rapidly
for SM to follow
• Change Safety program
logic to guarantee more
time between output
changes.
0x0312 Undertemperature All
• Under-
temperature at
microcomputers
• Under-
temperature at
I/O
Shutdown due to
violation of low
temperature limit
value in the SM
case
• Check the ambient
temperature.
• Once the fault
has been eliminated,
the
power must be
switched off
and on.