RS485 Coupling RE and DE

[rhnrgn]

Hello,

I am confused where should i connect RE and DE to same pin and where shouldn't.

It is easier to use it while they are coupled but what is the drawback of it?

I think it is about full duplex or half duplex but is it possible to listen rs485 line while transmitting?

Why should i full duplex instead of half duplex?

Can you enlight me?

Not1:I am microchip pic16f1946 user.
Not2:I am using Texas Instruments SN65HVD3086E

Thank You

 

[GUMY]

RS485 is half duplex line (2 wire) and RS422 is full duplex line (4 wire). On RS485 also Y-A and Z-B pins are joned together. So it depends on what You have on the other side of the communication line.
You can not transmit and receive at the sime time on half duplex lines (that is why it is called half duplex).