Yes. During commissioning you can assign the CPU with the higher MAC address to "A" .
1: Power up the CPU with the higher MAC address.
2: Using the keypad on the CPU assign the "A" attribute to the CPU.
3: Download the application to the PLC and issue a start command.
4: Power up the Standby while holding down the ESC key on the keypad.
5: When the screen displays "Erasing All RAM wait 2 seconds" let go of the ESC key.
6: The CPU should become Standby and take on the "B" attribute.
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