... distance, square wave output. <1>Smith-I (two-wire, 5 V supply), Smith-II (two-line system, ... Smith-I,II,III<2>Feature1,Adopt to second-wire system 2,Non-contact 3, The long transmission ... voltage: DC5V, 12V,24V. 4, Far Distance: 1 km (metal wire resistance ≤ 390 ω) 5, The ambient temperature: -40 ~ ... DC5V, 12V, 24V.4,Far Distance: 1 km (metal wire resistance ≤ 390 ω)5,The ambient temperature: -40 ~ + ...