English
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.3.10.1.2 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. 3.11.3.1).
Fig.3.11.1.1 Connection of RS-485 interface of submodule MR-0112