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Thread Closed: Became flame-war

???
04/24/08 09:38
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 		 #153945 - Address+Mask - an RF twist
Responding to: ???'s previous message
Russ Cooper said:
After the master sends an address/mask pair, it listens for the slaves' responses. The master can distinguish among these possibilities:
  • No slaves respond
  • Exactly one slave responds
  • More than one slave responds

    • With an RF link, I think that might be better stated as:

    After the master sends an address/mask pair, it listens for the slaves' responses. The master can distinguish among these possibilities:
  • No response received
  • A valid response received
  • A corrupt response received

    • The master might then make the assumption that "No response received" means "No slave responded" and that "valid response received" means "Exactly one slave responded" - although there is a margin for error there (certainly much greater than on a wire link)

    But the interpretation of a corrupt response is trickier: it could just be a garbled response from a single slave, or the result of multiple slaves responding...


    List of 115 messages in thread
    TopicAuthorDate
    Wireless network            01/01/70 00:00      
       assign address to each slave?(with "jumpers")            01/01/70 00:00      
          Still you wont know which is which?            01/01/70 00:00      
             pay with time            01/01/70 00:00      
                not easy            01/01/70 00:00      
                or pay with money            01/01/70 00:00      
                   or pay with money - not a solution            01/01/70 00:00      
                      Inherently not simple!            01/01/70 00:00      
             you cant poll for N number of slaves            01/01/70 00:00      
                 automatic            01/01/70 00:00      
                   N?            01/01/70 00:00      
                      N? - any            01/01/70 00:00      
             Ho about this ...            01/01/70 00:00      
                how do you propose to do that?            01/01/70 00:00      
                   have a look at the picture on the website            01/01/70 00:00      
                      Obviously missing something here...            01/01/70 00:00      
                      dipswitch my butt            01/01/70 00:00      
                         it\'s pretty obvious, isn\'t it?            01/01/70 00:00      
                            first - then            01/01/70 00:00      
                               Once again you're assuming facts not in evidence            01/01/70 00:00      
                                  The sample is much larger now            01/01/70 00:00      
                                     example            01/01/70 00:00      
                                        Yes, it is            01/01/70 00:00      
                                     I like that ...            01/01/70 00:00      
                I Don't get it either.            01/01/70 00:00      
                   It's reall not that complicated ... but ...            01/01/70 00:00      
                      Still not with you            01/01/70 00:00      
                      Slaves to broadcast their presence HOW?            01/01/70 00:00      
                         Not that difficult            01/01/70 00:00      
                            Thats fine but what if we have            01/01/70 00:00      
                               Then you really do need a database!            01/01/70 00:00      
                                  you WILL get in big doo-doo            01/01/70 00:00      
                                     this is absolutely true!            01/01/70 00:00      
                               You\'ll need lots of switches and lots of ports            01/01/70 00:00      
                                  totally off the rocker            01/01/70 00:00      
                                     How long, at 8kbps            01/01/70 00:00      
                                        Who on Earth wants to do that            01/01/70 00:00      
                                           One has to set limits            01/01/70 00:00      
                                              It does not have to be manual            01/01/70 00:00      
                                                 It has its "baggage"            01/01/70 00:00      
                                                    no "significant burden" who cares about 'simpler'            01/01/70 00:00      
                                                       Maybe we need to bring the O/P back to reality            01/01/70 00:00      
                                                          I can't tell            01/01/70 00:00      
                                                             I may be slow today....            01/01/70 00:00      
                                                       ARP possiblities            01/01/70 00:00      
                                                    Overhead - but possibly not too serious?            01/01/70 00:00      
                                                       You may be onto something ...            01/01/70 00:00      
                                                          you don't get it            01/01/70 00:00      
                                                             How long would it take?            01/01/70 00:00      
                                                                quicker than what?            01/01/70 00:00      
                                                                   Obviously there's a trick involved            01/01/70 00:00      
                                                                      or ...            01/01/70 00:00      
                                                                         no patent ...            01/01/70 00:00      
                                                                            With that scheme you have to skip some            01/01/70 00:00      
                                                                               easy            01/01/70 00:00      
                                                                                  No ... it means there's nobody at that one address            01/01/70 00:00      
                                                                                     Not an address, an address mask            01/01/70 00:00      
                                                                                        not likely on low-cost RF            01/01/70 00:00      
                                                                                           of course, but nobody woud dream of sending RF w/o            01/01/70 00:00      
                                                                                              Miracle ? , I differ            01/01/70 00:00      
                                                                                     confound it reat the stuff            01/01/70 00:00      
                                                                            no patent ... And after slaves colliding            01/01/70 00:00      
                                                                               after each 'find' it get faster            01/01/70 00:00      
                                                                                  the cheap RF links are typically            01/01/70 00:00      
                                                                   Erik, please clarify one point            01/01/70 00:00      
                                                                      If one could devise a suitable RF protocol...            01/01/70 00:00      
                                                                         the key is to know more than is known here            01/01/70 00:00      
                                                                            confound it can't you read            01/01/70 00:00      
                                                                               You're assuming facts not in evidence.            01/01/70 00:00      
                                                                                  if a response comes, your code is faulty            01/01/70 00:00      
                                                                                     So ... how does that differ from not transmitting?            01/01/70 00:00      
                                                                                        Richard, Richard            01/01/70 00:00      
                                                                                           Yes, but what SHOULD happen?            01/01/70 00:00      
                                                                                           with a mask of zero any unassigned sign sho            01/01/70 00:00      
                                                                                              What is it you are recommending, Erik?            01/01/70 00:00      
                                                                                                 Nothing I feel            01/01/70 00:00      
                                                                                                 Reading Erik's mind            01/01/70 00:00      
                                                                                                    Address+Mask - an RF twist            01/01/70 00:00      
                                                                                                       let me clarify            01/01/70 00:00      
                                                                                                    Russ, I admire your "psychic abilities'            01/01/70 00:00      
                                                                                                       A refinement            01/01/70 00:00      
                                                                                                          yes            01/01/70 00:00      
                                                                                                             Starting over            01/01/70 00:00      
                                                                                                                Russ, you may very well be right            01/01/70 00:00      
                                                                                                       Erik, that is not what was asked for!            01/01/70 00:00      
                                                                                                          whic i would have done ...            01/01/70 00:00      
                                                                                                             Perhaps you\'re not aware ...            01/01/70 00:00      
                                                                                                                1) abd 2)            01/01/70 00:00      
                                                                                                 NOT "mask address" but "mask AND address"            01/01/70 00:00      
                                                                            some things you can do on the one-wire channel            01/01/70 00:00      
                                                                               Very tricky indeed            01/01/70 00:00      
                                                                                  I do not ASS U ME diddlysquat            01/01/70 00:00      
                                                                               It is absolutly required for my scheme            01/01/70 00:00      
                                                                                  That is a non-starter with low-cost RF.            01/01/70 00:00      
                                                                      sorry            01/01/70 00:00      
       OK, here's an idea            01/01/70 00:00      
          collisions avoidance ?            01/01/70 00:00      
             Surely the master needs to know its slaves?!            01/01/70 00:00      
                identifying slaves            01/01/70 00:00      
             I can not help with collisions but..            01/01/70 00:00      
       multimaster via RF            01/01/70 00:00      
          collision recovery            01/01/70 00:00      
             Not a few seconds            01/01/70 00:00      
             Listen Before Xmit            01/01/70 00:00      
                not that urban legend again            01/01/70 00:00      
                   Accepted terminology            01/01/70 00:00      
                Collisions will still happen            01/01/70 00:00      
                   Yes, but how will the system respond?            01/01/70 00:00      
                Listen Before Xmit ......            01/01/70 00:00      
                   if slaves can "speak without being spoken to"            01/01/70 00:00      
       Perhaps you should read this article            01/01/70 00:00      
        A Better Way             01/01/70 00:00      
          There are some internal issues too            01/01/70 00:00      
             frequency hopping            01/01/70 00:00      
                frequency hopping , I have DSSS            01/01/70 00:00      

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