33  FUNCTIONS
33.1  Safety Operation Mode
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Safety operation mode state transition
The Safety CPU retains the safety operation mode even in the event of a power failure, and therefore the current safety 
operation mode state will remain unchanged even if the CPU module is powered off and on or is reset. Safety function 
modules do not retain the safety operation mode in the event of a power failure, and the safety operation mode will be the 
same as that of the Safety CPU when the CPU module is powered off and on or is reset.
If [Online]  [User Authentication]  [Initialization of all PLC Data] is performed, the safety operation mode 
will revert to the default mode (TEST MODE). All programmable controller information can be initialized 
regardless of the safety operation mode.
Safety operation mode 
state
Status transition by operation
Power off  on or reset Safety operation mode switching operation
TEST MODE  SAFETY MODE SAFETY MODE  TEST MODE
TEST MODE  TEST MODE  SAFETY MODE (wait-for-restart) 
SAFETY MODE  SAFETY MODE   TEST MODE
SAFETY MODE (wait-for-restart)  SAFETY MODE   TEST MODE
TEST MODE
The Safety CPU is 
powered off and on 
or reset.
Mode switching
(SAFETY MODE → TEST MODE)
• Factory default
• When the safety CPU operation mode 
  becomes unknown
Mode switching
(SAFETY MODE (wait-for-restart)
 → TEST MODE)
Mode switching
(TEST MODE → SAFETY MODE)
SAFETY MODE
The Safety CPU is 
powered off and on 
or reset.
SAFETY MODE
(wait-for-restart)
The Safety CPU is powered on 
or reset.