Hi,

Claudio Rachiele IW0DZG wrote:
>
> Try to connect the MASTER TX to SLAVE#1 RX, SLAVE#1 TX to SLAVE#2 RX and so on
> until SLAVE#last TX to MASTER RX.
> Of course each command and/data must have generation and destination  address
> and each slave must have its oun unique
> address and a pass routine to propagate the data that not belong to it.
> You can check that everything work if when you send a cmd for an address that
> doesn't exist you got the same back at your master.
> On Dontronics site you can download PICEX code that have the pass routine.
> If you don't want to program the slaves Dontronics can sell you programmed
> 16c57(remember to ask for different ID).
>
>                        Claudio Rachiele IW0DZG


I would recommend a different topology using RS-485 Driver e.g. TI 75176
or similar.
get a data-sheet for RS485 Line-Drivers there will be the Idea better
explaned.
Disatvantage: you need to implement a protokoll which handles collisions
if multimaster. If you just poll each nod with one Master it4s "easy".

In the Idea above, mentioned by Claudio there is the main disadvantage
that if on node fails the whole loop will become unaccessible.

Kind regards

        Stefan Sczekalla-Waldschmidt DB8FW
        ssw@oikossw.de