6
K1 (R) and K2 (R) represent the forcibly guided N/C contacts for monitoring the state of the
relay (readback contacts).
To use the function for external contact monitoring, wire the N/C contacts to the alarm input
IN1 and IN2 as illustrated. In this case, the alarm inputs must be assigned to the outputs.
Parallel connection of the alarm contacts is not permitted.
These contacts can also be read via safe digital inputs. In this case, evaluate the readback
and thus the state of the actuators in your safe application program.
When calculating the SIL values for both alternatives, take the different failure rates into
consideration.
Basic specifications
OUT0_Ch2_13
Output 0, channel 2, contact 13
OUT0_Ch2_14
Output 0, channel 2, contact 14
UT1 (UT2)
Clock output UT1 or UT2
IN1 (IN2)
Alarm input IN1 or IN2
UT2 (UT)
Clock output UT2 or UT1
IN2 (IN1)
Alarm input IN2 or IN1
WARNING: Loss of the safety function due to external supply
Make sure that no cross circuits can occur.
Actuator
Two-channel
Achievable
SIL/SIL CL/Cat./PL
SIL 3/SIL CL 3/Cat. 4/PL e
External errors that can be
detected
If alarm inputs IN1 and IN2 are used:
1.
An external load does not pick up
2.
An external load does not drop out
Errors that cannot be
detected
If no alarm inputs are used, no errors can be detected in the external load or in the wiring.
External wiring
requirements
The user is responsible for error analysis for the connected loads and for the external
wiring.
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User manual IC220SDL840 -
May 2018
GFK-2734