Hello,

I´m trying to connect to hart loop with sensor siemens sitrans LR460 level transmitter(4-20mA,hart compatible) using hart communicator 375 emerson.

I wire hart with sensor exactly like on screen in attachment with one change that i always disconnect wires from analog input card in local control box and then i connect them with hart throught resistor on negative wire , these LR460 sensors are all active and have own powered mA loop so i don´t need source of power .

Hart is still unable to find sensor device , i don´t know where problem could be.

When i do DC voltage measurmet test on hart it shows around 23V , which is strange as long as i used resistor in loop .

I also changed in Poll address range from 0 to 0-63 , didn´t also help.

Last thing i tried was downloading  EDD´S from siemens for this LR460 sensor i copied them on memory card , but they were here all the time because when i have been copying files to memory card it asked me to replace same named files.

The sensor is difficult to access , it is in dangerous height  , so i have only option to connect on it´s wires from local control box ,taking them off the analog input card.

Any help would be appreciated .

Thanks