B&B Electronics Asynchronous to Synchronous Converter 2010 Manuel d'utilisateur télécharger pdf (Page 22)

Department of Computer Science and Electronics

The MAX489 transceiver’s pins RO, DI, and DE are connected to the

microcontroller’s pin PD0, PD1 and PD2 respectively.

Figure 4-5 is the pin configuration of Atmega16 and MAX489 transceiver. The

PD0 pin is used as an RXD pin to receive data using USART (The Universal

Synchronous and Asynchronous serial Receiver and Transmitter). In the same way the

PD1 pin, also called TXD, is going to be the transmitter pin. The PD2 pin is configured

as an input and is connected to the transmission Enable pin of the transceiver. The

purpose of using this Enable signal is to connect the driver to its output terminals, A and

Y. If the Enable signal is OFF, one can consider the driver as disconnected from the

transmission line. An RS-485 driver must have the Enable control signal. [3]

Finally, the connection between the transceiver and the RS485 network is made

using the sockets shown in figure 4-6.

Figure 4-5. Atmega16 and Max489 pin configuration

Figure 4-6. Connection between MAX489 and sockets

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 42 43

Pas de commentaire

B&B Electronics Asynchronous to Synchronous Converter 2010 Manuel d'utilisateur Page 22