[bascom] RS485

["Eric Le Baron" <er.lebaron@hccnet.nl> (by way of Michel van Deventer <michel@het.grote.net>)]

Hi all,

For my project I will have about 10 modules interconnected by rs485.
Total cable length less than 100 metres and the baudrate 115K2.
Each module will have its own address.
3 modules will have a display and a keypad and must be able to quickly
retrieve actual data from the 7 modules.
This could be done on-demand or whenever the data of one of the modules
changes.
For the communication I will use the 9-bit format where the 9th bit will
determine whether the byte represents an address or data.
The packet length will be 64 bytes at most and the overall traffic on the
network will be light.

I've been reading Jan Axelson's book "Serial port complete" but I do not
want to use a master/slave or token-passing protocol and she says that the
collision detecting protocol is not suitable for rs485 ?!

I'm hereby seeking for general advise, dos and donts.
A possibility to upload the program over rs485 would be fantastic.

Thanks,

Eric Le Baron
Wageningen
The Netherlands