>-----Original Message-----
>From: Alan B. Pearce [mailto:A.B.Pearce@RL.AC.UK]
>Sent: 23 June 2004 08:38
>To: PICLIST@MITVMA.MIT.EDU
>Subject: Re: serial port dilemma - design advise requested
>
>
>>>Add a "time to live" byte, that is decremented by each widget, to
>>>prevent packets from looping forever.
>>
>>Trouble with this approach is that two serial ports per PIC would be
>>required, and only the newer(and larger) 18F support this in hardware.
>
>No you need only one serial port, and the connection goes
>around a ring in token ring network style.
>

Alan,

I don't understand how the scheme would work in that case.  The suggestion
by David VanHorn was that a packet is sent to a PIC.  If the packet is not
destined for that PIC, it is sent onto the next one.  This implies (to me at
least) that the PIC's are daisy chained, and the PC always talks to the
first one in the link.

If this implemented with a common bus, then all the PIC's would receive the
packet at once, so there would surely be no need to keep sending it on?

Regards

Mike




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