Purpose
LT module is used to termination of signal line  (UTP cable) between devices exchange data according to the standard MODBUS protocol on the network RS-485.
 

Functioning
Termination is the ending of signal line (UTP cable) suitable resistances in order to maintain a uniform wave resistance of the all line, which significantly improves the quality of data transferred and eliminates errors in the signal line.
Polarisation of the line make in the case when at least one slave devices on the network RS-485 doesn’t have a signal point GND. Polarisation could be make only for a MASTER device. 
    

Technical data