1．用1～5各开关模拟5个病房的呼叫输入信号，1号优先级最高；1～5优先级依次降低；

2．用一个数码管显示呼叫信号的号码；没信号呼叫时显示0；有多个信号呼叫时，显示优先级最高的呼叫号（其他呼叫用指示灯显示）；

3．凡有呼叫发出5秒的呼叫声。

-1. ~ 5 with a simulation of the switch five wards Call input signal, the No. 1 high-priority; 1 ~ 5 lower priority order; 2. Using a digital signal Display call the number; When the call did not signal indicates 0; Many call signal, show high-priority calls (calls with other indicators show); 3. Where call issued five seconds whoop.