Technical Discussion
LCD
The liquid crystal display (LCD) is driven by the CPU. The LCD displays the
patient's %SpO
and pulse rate. The LCD also displays icons indicating the status
2
and functions of the monitor. Refer to the O
M
N-65 Operator's Manual for a
XI
AX
description of the icons.
IrDA
The IrDA (Infrared Data Association) is an industry standard for infrared
communications. The IrDA receives information from the CPU, converts it, and
sends it to an external printer. The external printer communicates with the IrDA.
Refer to the printer manual for more information.
Power Supply
The user interface PCB power supply receives power from the SpO
PCB power
2
supply. The power supply provides a regulated 3.0 volts DC to the CPU.
Power Supply Monitoring
The power supply outputs are monitored by the power monitoring function to
ensure stability. The power supply monitoring circuit sends a reset signal to the
watchdog circuits to shut down the monitor when voltages are out of tolerance.
The power supply monitoring circuit monitors the battery output voltage and shuts
down the monitor when the battery voltage is critically low. The circuit provides
the low battery signal.
O
M
N-65 Service Manual
87
XI
AX