Translations:WB-MRM2-mini Modbus Relay Modules/19/en
If the device is the last one on the RS-485 line, a 120 Ohm resistor-terminator must be installed between its inputs A and B. Practice shows that in the case of bench tests with a small length of the RS-485 line and a small number of terminator devices on the last device in the line can not be installed.