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???
02/14/07 13:20
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 		 #132891 - V+ and V-
Responding to: ???'s previous message
You can check if the charge pumps work OK by measuring voltages on their filtering capacitances at the V+ and V- pin.

Even if you don't have an oscilloscope, with a standard DMM, you might be able to see a drop in the static voltages on the Rx/Tx pins at both sides when transmitting continouosly a character with enough zeros, for example space (0x20). If you use Win on PC, get Terminal by Bray, it has a nice feature for this - you can set it to repeatedly transmitting a macro.

Check also the continuity of the cable you are using; especially of the ground connection!

JW


List of 30 messages in thread
TopicAuthorDate
how do we test whether MAX232 is working            01/01/70 00:00      
   V+ and V-            01/01/70 00:00      
   Can I conclude then...            01/01/70 00:00      
      checking for working of serial port            01/01/70 00:00      
         You have excluded the most obvious first?            01/01/70 00:00      
   Be sure the cable is wired correctly            01/01/70 00:00      
      3 Wire            01/01/70 00:00      
         That doesn't seem to work with my old notebook            01/01/70 00:00      
            Configure the terminal program correctly            01/01/70 00:00      
               So far, It's never been an issue            01/01/70 00:00      
                  It's the application, not the PC            01/01/70 00:00      
      It's the application, not the PC            01/01/70 00:00      
         I have routinely done this in the past            01/01/70 00:00      
            Ive seen it working...            01/01/70 00:00      
               You missed my point            01/01/70 00:00      
                  Better safe than sorry, Eh?            01/01/70 00:00      
                     it's not all in the application            01/01/70 00:00      
                        but the OP stated            01/01/70 00:00      
                           True enough ...            01/01/70 00:00      
                        Now, now, we don\'t split hair do we?            01/01/70 00:00      
                           keep splitting :-)            01/01/70 00:00      
                           I've been fiddling with RS232 connections ...            01/01/70 00:00      
                     Ok, enough of twist and turn....            01/01/70 00:00      
                        I don\\\'t see what\\\'s not straight about this            01/01/70 00:00      
                           This has gone far enough.            01/01/70 00:00      
                              Guys, guys            01/01/70 00:00      
                              OK ,,, I see what you mean            01/01/70 00:00      
   @site administrator            01/01/70 00:00      
   @site administrator            01/01/70 00:00      
      Again... What was the solution?            01/01/70 00:00      

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