Mindray DPM 4

2-16
2.2.7 Button Panel
2.2.7.1 General
This module provides a man-machine interactive interface.
2.2.7.2 Principle diagram
Figure 2-10 Working principle of the button panel
2.2.7.3 Principle
This module detects the input signals of the button panel and control knob, converts the detected
input signals to codes and then sends to the main board. The main board sends commands to the
button panel, which, according to the commands, controls the status of the LED and the audio
process circuit to give auditory/visual alarms.
CPU
 Detecting the input signal of the button panel and control knob;
 Controlling the status of LED;
 Controlling the audio process circuit;
 Regularly resetting the Watchdog timer;
 Communicating with the CPU board.
Audio Process Circuit
This circuit generates audio signals and drives the speaker.