-as long as the circuit breaker with micrologic P is closed, the network voltage supplies the micrologic. So even if the current drops below 0.2In, the display stays on and current/voltage can be read.
-if the breaker is open, and no external 24Vdc auxiliary power supply, the display goes off
-if the breaker is open and an external 24Vdc auxiliary power supply is connected to micrologic, the display goes on and current/voltage can be read (0A for the current obviously as the breaker is open, and 0V for the voltage if the device is energized by upstream.
The PTE option allows to measure voltage even when the breaker is open.