Engineering
36
HR9Z-B2192 8/2020
State Transitions
NOTE: Refer to the Activation and Deactivation
(see page 40)
for details on the use of the terms
“activated” and “deactivated” in the present document.
Example with Emergency Stop
The following example uses a machine with an Emergency Stop pushbutton, a start pushbutton for
manual start, and a motor to demonstrate the individual operating states and state transitions. The
selected application function is Monitoring of Emergency Stop Circuits. The selected start function
is Manual Start. The example assumes that the equipment is properly wired and configured.
After the device is powered on, it enters the operating state Initialization (T1).
If the initialization is successful, the device enters the operating state Run: Outputs Deenergized
(T2).
If an error is detected, the device transitions to the operating state Error (T5).
On entering the operating state Run: Outputs Deenergized, the device verifies the state of the
safety-related inputs and of the start input. The motor is at a standstill.
If the start pushbutton is not pressed, the start input stays deactivated and the device remains
in the operating state Run: Outputs Deenergized. The motor is at a standstill.
Detailed information on the start functions and the timing can be found in the chapter Start
Functions
(see page 65)
.
If the start pushbutton is pressed, the start input is activated, i.e. the start condition is fulfilled.
The state of the safety-related inputs determines whether the device transitions to the operating
state Run: Outputs Energized.
State transition Condition
T1
Power on
T2
Initialization successful
Switch on delay has passed
T3
Start condition fulfilled (for example, automatic start or manual start with start
button pressed)
Safety-related inputs activated
For application functions with signal interlock monitoring: no signal interlock
condition
For application functions with synchronization: synchronization time
requirements met
T4
Safety-related inputs deactivated (corresponds to triggering of the safety-
related function)
T5
Error detected on
T6
Power off
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