On Friday 27 May 2005 09:32 am, Olin Lathrop scribbled:
> I agree this is all possible.  I was just trying to get Neil to realize
> that while RS-485 can be made to do what he wants, there are a lot of
> sticky details that are going to make a robust implementation tricky, or at
> least a lot more work than he seems to think.

Totally understand and expect that.  My only communications code to date was a 
terminal program with xmodem/ymodem I did on Win3.1 eons ago.  But I have 
some idea of RS232 communications and acks, naks, etc.

Any communications will require some head-scratching, but I still feel this is 
relatively simple, especially considering my non-critical messaging.  When a 
station sends out a signal, the master will distribute it to a number of 
other stations requiring it, including the original sender.  A light on that 
original sender will go on to indicate the activity/state, so that in itself 
will count as an acknowledgement.  If an error occurs, the sender (person) 
will just re-send the signal.

It is difficult to see all of the potential failure points from this 
bird's-eye view currently, so I'm waiting on some of the RS485 transcievers 
to come in so I can mock-up a few stations and really see what I'm in for.

Cheers,
-Neil.


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