用PLC设计一个主持人控制的抢答器？

主持人给出题目后，按下抢答按钮，开始抢答信号灯亮后可以抢答，先按下按钮的抢答指示灯亮，后按下抢答按钮的抢答指示灯不亮；如果主持人未按下开始抢答按钮而有人抢答，则对应的抢答指示灯闪烁起来，表示犯规，等主持人按下复位按钮后，则可重新进入抢答环节。

接线图略。

#define PlayerKey1_IO (P01)
#define PlayerKey2_IO (P02)
#define PlayerKey3_IO (P03)
#define PlayerKey4_IO (P04)
#define PlayerLED1_IO (P11)
#define PlayerLED2_IO (P12)
#define PlayerLED3_IO (P13)
#define PlayerLED4_IO (P14)
#define BuzzerEnable_IO (P15)
void SysInit(void)
{
//设置Key_io为上拉输入
//设置LED_io为通用输出
//设置BuzzerEnable_io为通用输出
}
unsigned char KeyScan(void)
{
if (PlayerKey1_IO == 0) return 1;
if (PlayerKey2_IO == 0) return 2;
if (PlayerKey3_IO == 0) return 3;
if (PlayerKey4_IO == 0) return 4;
return 0;
}
void Delay_Ms(unsigned char Nms)
{
volatile unsigned short tempcnt;
while (Nms--)
for (tempcnt = 0; tempcnt < 500; tempcnt++);//按照相应的参数配置计数上限，此处设为500
}
void main(void)
{
unsigned char MarqueeStep=0;
unsigned char KeyValue=0;
SysInit();
while (1)
{
Delay_Ms(400);
KeyValue = KeyScan(); //无按键去抖
if (KeyValue == 0)
{
MarqueeStep++;
if (MarqueeStep > 4) MarqueeStep = 0;
BuzzerEnable_IO = 0; // 按键取消停止蜂鸣器发声
}
else
{
MarqueeStep = KeyValue;
BuzzerEnable_IO = 1; //蜂鸣器发声
}
PlayerLED1_IO = 0;
PlayerLED2_IO = 0;
PlayerLED3_IO = 0;
PlayerLED4_IO = 0;
if (MarqueeStep == 0)
PlayerLED1_IO = 1;
else if (MarqueeStep == 1)
PlayerLED2_IO = 1;
else if (MarqueeStep == 2)
PlayerLED3_IO = 1;
else if (MarqueeStep == 3)
PlayerLED4_IO = 1;
}
}
基础框架是这样。

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