2
2.7
Alarm inputs IN1 and IN2
The module has two alarm inputs, IN1 and IN2, which only operate together with the
assigned clock outputs, UT1 and UT2. They are used for contact monitoring for externally
connected switching elements. This function can be used to monitor the contacts of
externally connected switching elements. The monitoring function is performed locally on
the device and does not have to be carried out in the safe application program.
As an option, the monitoring function can be parameterized and assigned to a relay output.
Parameterization
The assignment of clock outputs to alarm inputs is fixed and cannot be parameterized.
The assignment of an alarm input to a relay output is specified during parameterization of
the relay output.
Technical data
For the technical data for the alarm inputs, please refer to page 11-7.
Error detection and
behavior in the event of an
error
The status of the alarm inputs is constantly compared with the desired status of the
assigned outputs. In the event of deviations, the affected outputs are switched off and a
diagnostic error message is sent to the safe controller.
Through the dynamization of signals and the corresponding expected behavior in the
device firmware, all errors, which can occur internally in the circuit or externally in the
wiring, are detected.
Diagnostics
Diagnostics of the alarm inputs are provided via both the local diagnostic indicators and the
diagnostic messages, which are transmitted to the safe controller.
For information about the diagnostic messages of the alarm inputs, please refer to Section
"Safe digital relay output errors" on page 9-3.
The diagnostic data is not safety-related. This data must not be used to execute safety-
related functions.
If an alarm input is assigned to the relay output, ensure that:
When an output is switched off, the output can only be switched on again after 300 ms
because the internal circuit is subject to internal checks during this time.
Alarm inputs IN1 and IN2 can only be assigned to an output once. Parallel connection of
the alarm contacts is not permitted.
For two-channel assignment, both outputs are switched off if an alarm input indicates an
error.
2-8
User manual IC220SDL840 -
May 2018
GFK-2734