Operating modes and functions
5.1
Actuator shutdown
Actuator shutdown
The actuator shutdown is a function that allows digital outputs DO to be set to a digital low level
via a monitoring channel (DI channel) of the CFU. This is done directly by the CFU without
coordination through the CPU.
Actuator shutdown in the CFU
The actuator shutdown of the CFU uses a monitoring channel (DI channel) to rapidly set all the
digital outputs to a digital low level.
When the actuator shutdown shuts down the digital outputs, the CFU generates a diagnostic
interrupt.
CFU PA: The function has no effects on the PROFIBUS PA channels (FB x).
Note
Connection to the CPU
Actuator shutdown takes effect independently of the connection to the CPU (STOP/RUN,
connection interrupted) and the configured substitute values.
"Monitoring channel" parameter
Selection of the monitoring channel used to switch off the digital outputs.
Settings:
● None
● Channel 0
● Channel 1
● ...
● Channel n
Ensure that the selected channel is activated and is the "Digital input" type.
"Switch off at signal level" parameter
Select the signal level at which the digital outputs are to be switched off.
SIMATIC CFU
Commissioning Manual, 08/2019, A5E39252870-AD
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