plc程序管廊1.　　选择运行稳定，使用寿命长的工业中高端PLC;
2.　　能耐受温度、湿度、腐蚀性气体等恶劣的环境；
3.　　优良的性能，保证大网络的可扩展性和开放性；(plc programe guanlangrun; working; move; be in motion; circulate
life length; operational life span; working life; service life
high-end
temperature
humidity; dampness
active gases; corrosive gases
ill-being; rugged environment
excellent; good; fine; choiceness
extendibility
open; patent)