1 - 5
Theory of Operation
Main Unit
Alarm Lamp
The monitor has an alarm lamp on the front panel. The alarm LED board converts the electric
signals into visual signals and then sends the visual signals to the alarm lamp through a light
pipe. The alarm lamp illuminates either red or yellow, depending on how the alarm is
configured.
Recorder
The recorder receives data coming from the CPU board through a UART and then sends them
to the thermal print head for printing. The recorder has a hard key (starting/stopping
recordings) and a green LED on its front. It connects to the power management and interface
board.
The following diagram shows its operating principle.
FIGURE 1-4
Operating principle
MODULE
DESCRIPTION
Power supply interface
Introduces a DC from the CPU board.
Power module
Converts the input power into voltages that fit each module and
then forwards them to each module.
CPU
Controls the communications between modules.
Signal interface
Controls the communications between the CPU board and the
recorder CPU.
Drive circuit
Receives control signals from the CPU and then forwards them to
the stepper motor.
Recorder key board
Sends key commands to the CPU and receives commands from
the CPU to control the LED on the recorder.
FPC interface
Sends the thermal print head information to the CPU and
receives commands from the CPU to control the thermal print
head.
MAIN BOARD
POWER
MODULE
CPU
DRIVE
CIRCUIT
RECORDER
KEY BOARD
FPC INTERFACE
THERMAL PRINT HEAD
MOTOR
CONTROL
POWER
SUPPLY
CONTROL
POWER
SUPPLY
INTERFACE
KEY & LED
INTERFACE
SIGNAL
INTERFACE
