中文摘要及关键词
摘 要：我国北方冬季寒冷而漫长，大力推广蔬菜大棚种植蔬菜能够更好地满足人民日益提高的生活需要。
蔬菜大棚内通过调节温度可以有效地控制二氧化碳的浓度，二氧化碳是对植物生长起着重要的作用。因此，对棚内温度的控制是非常重要的。本文介绍的分布式单总线蔬菜大棚温度监测预警系统，采用全数字化设计，直接监测每个棚内不同部分的温度，通过对温度的良好控制，有效地提高蔬菜的产量。本温度设计采用现在流行的PLC控制，配以数字温度传感器，该温度传感器可自行设置温度上下限。单片机将检测到的温度信号与输入的温度上、下限进行比较，由此作出判断是否启动继电器以开启设备。
本设计还加入了常用的数码管显示及状态灯显示灯常用电路，使得整个设计更加完整，更加灵活。
关键词：蔬菜大棚；PLC；温湿度控制
英文摘要及关键词
Abstract: Long and cold winter in North China to promote vegetable greenhouses to grow vegetables to better meet the growing needs of people.
By adjusting the temperature inside the greenhouse vegetables can effectively control the concentration of carbon dioxide, carbon dioxide is plant growth plays an important role. Therefore, the greenhouse temperature control is very important. Introduced greenhouse vegetables distributed single bus temperature monitoring and early warning systems, the use of digital design, directly in its own monitoring of each part of the temperature, through good control of temperature, effectively increasing vegetable production. This design uses the current PLC control of temperature, with a digital temperature sensor, the temperature sensor can be set on the temperature lower limit. Microcontroller detects temperature signal is compared with the input temperature of the upper and lower limits, which make a judgment whether to start the relay to turn on the device.
This design also includes commonly used digital tube display and status LED indicator light circuit, making the whole design is more complete, more flexible.
Keywords: vegetable greenhouse PLC; temperature and humidity control
