施多德接近开关近接开关方型开关叉车专用传感器开关 LM12-3002NA-LD LM12-3004PA LM18-3005NA LM18-3005PA 三线 常开; LM12-3004NB LM12-3004PB LM18-3005NB LM18-3005PB 三线常闭施多德自动化; Output voltage dropDC/AC DC