4-20mA output introduction

Many industrial meters choose to use current to transmit signals, because current is not sensitive to noise.  The current loop of 4 ~ 20mA is 4mA to represent the zero signal, 20mA to represent the full scale of the signal, and the signal below 4mA and above 20mA is used for the alarm of various faults.  The 4-20MA output of Lanrui instrument products is active 4-20MA signal except water meter, micro flow meter and heat meter.  The output of the water meter 4-20mA is passive. Therefore, when the 4-20mA output of the two-wire water meter is used, the device receiving current signals must be active.   Time Difference series: M53-M58 menus are used to calibrate, set and verify the 4-20MA output.  

1. Doppler series meter : OUTPUT1 select 4-20 mA. Flow 4mA set the instantaneous Flow for 4 mA. Flow 20mA set the instantaneous Flow for 20mA. Water meter/Small flow series: The first digit of the CFU menu is set to 2 to turn on the current output.  

FF menu set 20mA to correspond to the instantaneous flow;  4mA indicates that the instantaneous traffic is 0 and there is no menu to set.  

2. Area-velocity series meter: in the Output submenu, select 4-20 ma and set the instantaneous flow of 4 mA and 20mA.  

3. Flume and weirs type open channel series: under flow parameter Settings, select 4-20 mA to set the instantaneous flow of 20mA and 0 for 4 mA. There is no menu to set.