At 17:25 19.6.1998 +0100, you wrote: 
>
> I am looking for information or coding using the RS485 protocol.
> Ê
> Can anyone provide me with information on this.
> Ê
> Your assistance is appreciated.


Huh ?

Maybe I am completely wrong, but I was almost sure that RS-485 is a definition
of electrical characteristics of the interface. AFAIK, RS-485 doesn't contain
any description of higher level protocol.

I am using normal RS-232 routines for communication over RS-485 interface
(LT491 chip). I implemented small set of routines (called HomeBus :-))) for
several communications in my home. Every house automation point has a PIC
which
is connected to RS-485 via 491 chip. I am using two pairs, so full-duples is
possible. To avoid collision detection and similar, I am using simple
solution,
which is probably well known. Master is using one pair for sending the packet.
The first byte of the packet is the address of the device. Every device has a
unique address. The slaves are responding on the other pair of wires. Slave to
slave communication is also possible, but only via master. I am using similar
principle as the old Arcnet networks - token passing on logical circle.
Works like a charm (hmm, almost :-)

PavelK

**************************************************************************
* Pavel Korensky                                                         *
* DATOR3 LAN Services spol. s r.o.                                       *
* Modranska 1895/17, 143 00, Prague 4, Czech Republic                    *
*                                                                        *
* PGP Key fingerprint:  F3 E1 AE BC 34 18 CB A6  CC D0 DA 9E 79 03 41 D4 *
*                                                                        *
* SUMMA SCIENTIA - NIHIL SCIRE                                           *
**************************************************************************