Safety Manager Safety Manual - Tuv-fs.com

4 – Safety Manager special functions
Figure 10 on page 40 shows how the output signal of the AND gate is connected
to the unit shutdown.
As long as all diagnostic inputs are “healthy”, they are High, the unit shutdown
output is High and the unit relay is activated (relay contact closed).
If a diagnostic input of an output channel in the unit becomes “unhealthy”, the
corresponding unit shutdown output becomes Low and the unit relay is
deactivated (relay contact open).
Figure 10 Functional logic diagram of unit shutdown
A defective output channel can be switched-off in accordance with the normal
Safety Manager response for safety-related signals. To switch off a defective
output channel, the calculated application output and the channel diagnostic input
must be supplied to the output channel via an AND gate.
The Safety Manager FaultReset alarm marker is connected to all unit
shutdown outputs via an OR gate. When an error is detected and repaired in a
unit, the unit may be restarted using the FaultReset alarm marker.
The minimum and maximum time the unit output is enabled by the
FaultReset is limited to ensure that the FaultReset is detected by the
output. The pulse length (typically set at 800 ms) may not exceed the Diagnostic
Test Interval.
40 Release 131, Issue 4.2