8 RS422 with Mega board ?

Graynomad:
There are a few dual, quad and even octal UARTs around, you may have to use them.

Are you talking about maxim chip ?

May I get an reference ? Before I post I was thinking about max488 x 8 to realize it.

PaulS:

Is NewSoftwareserial able to handle 8 serial stream at the same time ?

No. It can manage one stream at a time.

I don't need a real realtime. I was tinking with some piece of code like :

pseudo code !

void loop()
{

bool dataToSend = false;

for (in485=0; in485<7; in485++)   // check about data to send through the 8 485 ports.
{
   if (my485[in485].available()>0)   // there are some data, collect them
   {
       dataToSend=true;
       putDatasInBuffer(in485);
   }
}   
   if (dataTosend)   // make an udp packet and send it
   { 
      makeUpdPacketfromBuffer();
      sendUpdPacket();
   }

if (UpdPacketReceived)    // ok we've got datas that come from ethernet
{
  for (out485=0; out485<7; out485++)
  {
      ExtractAndWriteDataTo485(out485);   // get them an write it to the right destination rs485 out port
   }
}
}

Are you saying that newSoftSerial would not be able to manage it as fast ?

I don't want to collect datas into the computer. the connexion will be somting like :

RCP-1530#1 <-> 485#1-
RCP-1530#2 <-> 485#2-|<---->Mega <-> TCP/IP <-> Fiber<->TCP/IP <-> Mega <-> Camera#1, Camera#2, ...
RCP-1503#...
RCP-1530#8 <-> 485#8-/

It goes from Each RCP to his dedicated camera, without computer between.

Just want to multiplex 8 FullDuplex rs485 throug an 1GB oprtical fiber.