... Technical features:* 4-20mA, 3 wire connection ,compatible with existing alarm control unit or DCS(Distributed Control System) ... and maintenance. * Multi-parameter backlight LCD display: measuring range,digital gas reading ,units, bar graph , system status etc.* International ... ~ 45 VDC)* Linear output signal: 4~22.8mA with superimposed communication signal for HART protocol * Failure signal: 3 ...