Processor and communication modules 15.02.2020 08:27 15.02.2020 10:16

The MR-0112 submodule ensures the conversion of TTL signals of the serial interface to the RS485 interface galvanically separated. This interface works in half-duplex mode and allows multidrop connection of participants. The correct termination of the communication line is required for correct function (see below). The galvanic isolation of the serial interface is provided by the built-in inverter and no external power supply is required. For connection examples, see chapter 3.12.


Tab. Connection of serial channel connector A when the MR-0112 submodule is fitted (same applies to connector B)

Konektor A (B) Svorka Signál Typ signálu Užití

A2 BT– – výstup zakončení zakončení sběrnice RS-485
A3, A5 TxRx– – vstup/výstup RS-485 datový signál
A6 GND Napájení signálová zem
A7 BT+ + výstup zakončení zakončení sběrnice RS-485
A8, A10 TxRx+ + vstup/výstup RS-485 datový signál

The RS-485 serial interface submodule (type MR-0112, order no. TXN 101 12) is equipped with a complete bus termination circuit connected to terminals A7 (BT + signal) and A2 (BT– signal), see Fig. 3.11.1. The termination is connected to the bus by connecting the BT + and TxRx + terminals, resp. BT– and TxRx– (see example in Fig.

Fig. Connection of RS-485 interface of submodule MR-0112