IU是有源的吗,看你接着编如果是有源的,那还在停车场入口装ERP antenna干啥 ？？ Radio wave Frequency (center) : 2420 Mhz　 Reading Range : Up to 4m x 2m Make sure that there are no obstacles or objects within a radius of 50cm from the antenna, especially in front portion so that the radio wave is not block (more...)