Siemens LOGO! Series Manual page 65

You can also memorize four simple rules for starting LOGO! :
1. If neither LOGO! nor the inserted card contains a circuit program, the LOGO! Basic
2. A circuit program on the card is automatically copied to LOGO!. The circuit program in
3. If there is a circuit program in LOGO! or on the card, LOGO! adopts the operational state
4. If you have enabled retentivity for at least one function, or a function is permanently
Note
When a power failure occurs while you are entering a circuit program, the program in LOGO!
is deleted after power is returned.
Before you modify the circuit program, save a backup copy of your original to a card or to a
computer, using LOGO!Soft Comfort.
LOGO!
Manual, 04/2011, A5E03556174-01
displays the following:
LOGO! is overwritten.
it had prior to POWER-OFF. Versions without a display unit (LOGO!...o) automatically
change from STOP to RUN (LED changes from red to green).
retentive, the current values are retained at POWER-OFF.
LOGO! installation and wiring
2.4 Putting into operation
65