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Re: Serial protocol with physical decoding

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On 5/4/2017 3:48 AM, Don Y wrote:
> On 5/4/2017 12:28 AM, Jack wrote:
>> Il giorno giovedì 4 maggio 2017 08:13:50 UTC+2, Don Y ha scritto:
>>> I want to push a bit stream through a series of *identical* devices and
>>> have (identical) software running on each determine if that particular
>>> device is being addressed, or not.
>>>
>>> It seems like the simplest way to do so is to require each device to
>>> examine an address field in the packet and, if '0', assume the data that
>>> follows is intended for its consumption.  If not, decrement the address
>>> and pass the packet along.
>>
>>> Another downside is the cost of updating data on *all* (multiple)
>>> devices
>>> as this requires N messages.
>>
>> You can think of a special broadcast address that is not decremented
>> but the
>> device simply accept the message and ppass it over to the next.
>
> Yes, that's a good idea.
>
> My comment, above, was intended to deal with the case of sending
> DIFFERENT data to ALL devices vs. sending the SAME data to all
> of them.
>
> E.g., if I wanted to set the devices per the following table:
>
> ID    Value
> 3      CC
> 4      D
> 5      EEEE
> 6      FFF
>
> I could send the message (ignore the obvious error, here):
>
> 3CCDEEEEFFF
>
> device 3 to peel off the "CC" and pass "0DEEEEFFF" along which would cause
> device 4 to peel off the "D" and pass "0EEEEFFF" along which would cause
> device 5 to peel off the "EEEE" and pass "0FFF" along which would cause
> device 6 to peel off the "FFF", dissipating the message (i.e., devices
> 7 and higher would see no traffic)

What is the value of this vs. sending four messages?  You could send the 
message to 7 first.  Once that message has cleared the first unit send a 
message to 6, then 5, 4 and finally the message goes out to 3.  When 
message 3 is received by device 3 the message for 7 is being received by 
7.

-- 

Rick C

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Thread

Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-03 23:14 -0700
  Re: Serial protocol with physical decoding Clifford Heath <no.spam@please.net> - 2017-05-04 16:40 +1000
    Re: Serial protocol with physical decoding Mark Storkamp <mstorkamp@yahoo.com> - 2017-05-04 12:26 -0500
      Re: Serial protocol with physical decoding rickman <gnuarm@gmail.com> - 2017-05-04 15:46 -0400
  Re: Serial protocol with physical decoding Jack <jack4747@gmail.com> - 2017-05-04 00:28 -0700
    Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-04 00:48 -0700
      Re: Serial protocol with physical decoding rickman <gnuarm@gmail.com> - 2017-05-04 10:29 -0400
  Re: Serial protocol with physical decoding Reinhardt Behm <rbehm@hushmail.com> - 2017-05-04 16:44 +0800
    Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-04 07:09 -0700
  Re: Serial protocol with physical decoding Tim Wescott <tim@seemywebsite.really> - 2017-05-04 09:54 -0500
    Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-04 10:52 -0700
      Re: Serial protocol with physical decoding Robert Wessel <robertwessel2@yahoo.com> - 2017-05-04 14:53 -0500
        Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-04 13:17 -0700
          Re: Serial protocol with physical decoding Robert Wessel <robertwessel2@yahoo.com> - 2017-05-05 00:30 -0500
            Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-04 23:57 -0700
    Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-13 21:58 -0700
  Re: Serial protocol with physical decoding Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2017-05-05 00:50 +0200
  Re: Serial protocol with physical decoding Les Cargill <lcargill99@comcast.com> - 2017-05-04 18:47 -0500
    Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-04 20:07 -0700
      Re: Serial protocol with physical decoding Les Cargill <lcargill99@comcast.com> - 2017-05-07 09:21 -0500
        Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-07 10:22 -0700
        Re: Serial protocol with physical decoding Jack <jack4747@gmail.com> - 2017-05-08 00:04 -0700
  Re: Serial protocol with physical decoding Martin Riddle <martin_ridd@verizon.net> - 2017-05-06 12:14 -0400
    Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-06 12:29 -0700
      Re: Serial protocol with physical decoding Martin Riddle <martin_ridd@verizon.net> - 2017-05-08 18:53 -0400
        Re: Serial protocol with physical decoding Don Y <blockedofcourse@foo.invalid> - 2017-05-08 18:50 -0700

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