1.9 Auto power off and Idle Time selection
ES51911 has a default auto power off function. If the meter is idle for more than the
given Idle Time, the chip automatically turns the power off. The Idle Time to trigger the
auto power off function is determined by pin ‘APOSEL’. If pin APOSEL is connected
to V-, the Idle Time will be set to 30 minutes. If pin APOSEL is connected to DGND or
floating, the Idle Time will be set to 15 minutes. When APO happens, the state of the
meter is saved. The APO sign on the LCD panel indicates whether the auto power off is
enabled or not. In some cases, user might want to disable Auto power off. There are two
ways to disable this feature as following:
1. Power on the meter when any of the push functions, except for HOLD, is pressed
down.
2. In addition, when RS232 output is active, the auto power off function is also
disabled.
Note: Powering on the meter while pressing HOLD and lasts 2 seconds turns on all
LCD segments until HOLD is pressed again.
1.10 Sleep
The meter enters sleep mode after auto power off. The SLEEP pin asserts low (-3V) in
the sleep mode, and asserts high (+3V, not 0V) after re-power on.
1.11 Re-power on
After auto power-off, pushing any of the push function or changing the rotary mode can
turn on the meter again. If the meter is re-powered on by changing the rotary mode, the
saved state is cleared. If the meter is re-powered on by push functions, the chip restores
the saved state and enters HOLD mode. The LCD displays the saved value.
v1.2
12
11/09/06
CYRUSTEK [ Cyrustek corporation ]
