[elektro] full duplex rs485

[Sandor]

full duplex rs485?

"
RS485 meets the requirements for a truly multi-point communications network, and 
the standard specifies up to 32 drivers and 32 receivers on a single (2-wire) 
bus. With the introduction of "automatic" repeaters and high-impedance drivers / 
receivers this "limitation" can be extended to hundreds (or even thousands) of 
nodes on a network. RS485 extends the common mode range for both drivers and 
receivers in the "tri-state" mode and with power off. Also, RS485 drivers are 
able to withstand "data collisions" (bus contention) problems and bus fault 
conditions.

To solve the "data collision" problem often present in multi-drop networks 
hardware units (converters, repeaters, micro-processor controls) can be 
constructed to remain in a receive mode until they are ready to transmit data. 
Single master systems (many other communications schemes are available) offer a 
straight forward and simple means of avoiding "data collisions" in a typical 
2-wire, half-duplex, multi-drop system. The master initiates a communications 
request to a "slave node" by addressing that unit. The hardware detects the 
start-bit of the transmission and automatically enables (on the fly) the RS485 
transmitter. Once a character is sent the hardware reverts back into a receive 
mode in about 1-2 microseconds (at least with R.E. Smith converters, repeaters, 
and remote I/O boards).
"

Sándor

Fekete Róbert wrote:
> Üdv mindenki
> 
> érdeklődnék tud e ajánlani valaki full duplex rs485 ic-t
> ami kishaznénkban beszerezhető, lehetőleg 500-600 huf nál nem drágábban
> valami olyasmi kellene mint a 75176 csak fulduplex
> 
> előre is köszi
> 
> 
> FRob
> 
> www.harden.hu
> www.loudlink.eu
> 
> "Minden megoldható legalább egyszer
> és ha már egyszer megoldható..."
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