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???
01/02/08 07:17
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 		 #148900 - 10...15years ago
Responding to: ???'s previous message
In that time our telephone system was fully analogue and
all other equipment was not so advanced as today. So remote (in town) bank offices was connected trough cheap enough current loops adapters. This was used for remote offices of Water,Electricity and so on companies. I routed (for a friend company) PCB with 8 UARTs - 4 chips - and 8 current loop circuits. That card was ISA based, it was before Microsoft/Intel decided ISA to be killed.
regards
Happy new Year!

List of 56 messages in thread
TopicAuthorDate
Line driver IC            01/01/70 00:00      
   Telephone lines?            01/01/70 00:00      
   Slower analog solution..            01/01/70 00:00      
   That's a job for a transfomer!            01/01/70 00:00      
      line driver            01/01/70 00:00      
         Missing the point            01/01/70 00:00      
            Eh?? What is            01/01/70 00:00      
               Modem?            01/01/70 00:00      
                  Think Telco even if it's not            01/01/70 00:00      
               Have you read the datasheet?            01/01/70 00:00      
                  Not the modem speed            01/01/70 00:00      
                  What datasheet??????            01/01/70 00:00      
                     That is the datasheet            01/01/70 00:00      
                        I mentioned the chips and you say I havnt            01/01/70 00:00      
               No, you don't            01/01/70 00:00      
         Xformer only            01/01/70 00:00      
            at this low data rate (9600 bps) he could use AMI            01/01/70 00:00      
               AMI protocol            01/01/70 00:00      
                  who said anything about protocol?            01/01/70 00:00      
                     Difficult and with few software options            01/01/70 00:00      
                        Nobody said anything about a protocol            01/01/70 00:00      
                           Getting ahead of the questions            01/01/70 00:00      
                              fact is ... we don't have the information ...            01/01/70 00:00      
                                 Spare wire is already there . We do not            01/01/70 00:00      
                              Getting ahead of the questions            01/01/70 00:00      
                                 What type of wire and what environment?            01/01/70 00:00      
                                 please stop this mistreatment of a word            01/01/70 00:00      
                                    A Protocol is a set of guidelines or rules.            01/01/70 00:00      
                                    Apologies , I meant CODEC nor protocols            01/01/70 00:00      
         I am not sure...            01/01/70 00:00      
   27 or more solutions exist ...            01/01/70 00:00      
      ~9600bps            01/01/70 00:00      
         9600 is tough at that distance, so            01/01/70 00:00      
            Tough?            01/01/70 00:00      
               Not Tough? but costly.            01/01/70 00:00      
                  Still missing the point            01/01/70 00:00      
      He did specify the data rate            01/01/70 00:00      
         Where to apply modulation schemes when            01/01/70 00:00      
            Oh yes you have!            01/01/70 00:00      
            Driver/interface            01/01/70 00:00      
   no            01/01/70 00:00      
   Maxim Preemph RS-422 driver            01/01/70 00:00      
      FEET            01/01/70 00:00      
         speed and distance still apply            01/01/70 00:00      
            a pretty fancy rf link would fit the cable budget            01/01/70 00:00      
               Reverse engineer these            01/01/70 00:00      
                  Reverse engineer these            01/01/70 00:00      
                     buy one and find out            01/01/70 00:00      
                     Seems simple enough!            01/01/70 00:00      
                  Why not            01/01/70 00:00      
                     No black (box) magic methinks            01/01/70 00:00      
                        an other blackbox            01/01/70 00:00      
                           current loop vs balanced signal lines            01/01/70 00:00      
                              Have you ever heard of the teletype?            01/01/70 00:00      
                                 Bell system teletypes            01/01/70 00:00      
                              10...15years ago            01/01/70 00:00      

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