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???
11/15/06 15:00
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 		 #128024 - gprs and IP number
Responding to: ???'s previous message
Rob Klein said:
As you are using GPRS, you should be aware that, generally, the IP-address of your devices will not be fixed. That means it is extremely difficult, if not impossible, to have the device as a slave.
Rob.


I known this.
The idea is the device is always connected to GPRS network and you can setup a set of calling day/hour (there is a clock IC on the PCB).
When it's time to call the server the device call the server sending UDP pockets, autenticates and after this it becomes slave. At this point the server/master knows the IP number of the device and starts to send the commands it needs.

Optionally server can call the device, but only if he knows the IP number to call. This means the device was connected at least once.
However if , for some reason, the modem disconnected from GPRS net the device loose the IP number and server can call a wrong IP, in this situation the device don't respond and server must wait the next connection hour of that particular device (an report a warning).

Massimo.




List of 59 messages in thread
TopicAuthorDate
Right way to design/develop a protocol            01/01/70 00:00      
   Many ways....            01/01/70 00:00      
      SOAP            01/01/70 00:00      
         SOAP            01/01/70 00:00      
      State Machine.            01/01/70 00:00      
      SOAP - since you mention it...            01/01/70 00:00      
   I think            01/01/70 00:00      
      more SOAP...            01/01/70 00:00      
         two things to look at            01/01/70 00:00      
            Turning the bus            01/01/70 00:00      
               IIC turning the bus            01/01/70 00:00      
                  Turning the bus            01/01/70 00:00      
   A very important caveat            01/01/70 00:00      
      gprs and IP number            01/01/70 00:00      
   RFC953            01/01/70 00:00      
      Protocols            01/01/70 00:00      
         PC State Machines            01/01/70 00:00      
            why not switch()            01/01/70 00:00      
               Style            01/01/70 00:00      
                  Huh?            01/01/70 00:00      
                     Function Pointers!            01/01/70 00:00      
                        Function pointers troublesome? How?            01/01/70 00:00      
                           Overlay            01/01/70 00:00      
                              Table of function pointers            01/01/70 00:00      
                                 Experience helps            01/01/70 00:00      
                                    Up the Tree            01/01/70 00:00      
                                    No question at all!            01/01/70 00:00      
                                       Last word            01/01/70 00:00      
                                          Good luck!            01/01/70 00:00      
                                             Oh, he can            01/01/70 00:00      
                                                Living with the boss            01/01/70 00:00      
                                                   well, sometimes it does            01/01/70 00:00      
                                                      deja vu            01/01/70 00:00      
                                                         Take a hint from the Web            01/01/70 00:00      
                                                         Don't go into this menu            01/01/70 00:00      
                                          get another job            01/01/70 00:00      
                                             change job            01/01/70 00:00      
                                             All the news that's fit to print            01/01/70 00:00      
                                                I agree            01/01/70 00:00      
                              #pragma nooverlay in SDCC            01/01/70 00:00      
                              Update on function pointers            01/01/70 00:00      
                           are you using the awful LARGE model?            01/01/70 00:00      
                              Memory-model independant            01/01/70 00:00      
                                 not really            01/01/70 00:00      
                  No one size fits all            01/01/70 00:00      
   FTP?            01/01/70 00:00      
   relevatnt to your post, not thye subject            01/01/70 00:00      
      flash memory            01/01/70 00:00      
   Here's one.            01/01/70 00:00      
      Wrong thread sorry ^ ;)            01/01/70 00:00      
         Finite state machines            01/01/70 00:00      
            state machine            01/01/70 00:00      
   State Machines - AsyncPro?            01/01/70 00:00      
      Async Pro            01/01/70 00:00      
         Sounds like rubbish to me!            01/01/70 00:00      
         Need to hire some experience            01/01/70 00:00      
            Experience            01/01/70 00:00      
               Oh well            01/01/70 00:00      
            a very common mistake            01/01/70 00:00      

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