Sending a string and getting an odd result

Comments

• GregG Posts: 251

  June 2014

  Netlinx debug output tries to change all hex data into ascii printable characters if possible. $00 is not printable (like all the preceeding hex numbers) so it gets printed as the decimal number equivalent #0. But $57 in the ascii table lines up with the letter 'W' - so that gets printed into the debug output instead. ( ** So debug is showing that you sent what you wanted to send, the problem must be something else)
  
  Personally, I use debugging send_string 0 functions that I created for this, so I can get a more readable format in the telnet session.
  

  /////////////////////////////////////////////////////////////
  // Char[1000] PrintHex(Char cString[])
  //	Takes an incoming ASCii string up to MAX_PRINTHEX_INPUT chars
  // and outputs a hex byte representation of that string.
  // eg- cCmd = {$23,$5A,$FF} would print as:
  // "23:5A:FF"
  /////////////////////////////////////////////////////////////
  Define_Function Char[MAX_PRINTHEX_OUTPUT] PrintHex(Char cString[])
  {
  Stack_Var Char cOutput[MAX_PRINTHEX_OUTPUT]
  Stack_Var Char cTempStr[MAX_PRINTHEX_INPUT];
  Stack_Var Char cTmp
  
  	If (Length_String(cString) AND (Length_String(cString) <= MAX_PRINTHEX_INPUT))
  	{
  		cTempStr = cString;
  		cOutput = '"';
  		While(Length_String(cTempStr))
  		{
  			cTmp = Get_Buffer_Char(cTempStr)
  
  			cOutput = "cOutput,RIGHT_STRING("'0',ItoHex(cTmp)",2)";
  
  			If(Length_String(cTempStr)) cOutput = "cOutput,':'";
  		}
  		cOutput = "cOutput,'"'"
  	}
  	Else If(Length_String(cString))
  	{
  		_debug(__LINE__,DEBUG_NOTICE,"'PrintHex incoming string length: ',Itoa(Length_String(cString)),' exceeds maximum default, increase your constant size or break up your calls.'")
  	}
  	Return cOutput;
  }
  
  DEFINE_EVENT
  
  Button_Event[dvTP,1]
  {
          Push:
          {
                  Send_String dvProj,"$00,$85,$00,$D0,$01,$01,$00,$57"
                  Send_String 0,"'Sent to dvProj: ', PrintHex("$00,$85,$00,$D0,$01,$01,$00,$57")"
          }
  }
  

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• DHawthorne Posts: 4,584

  June 2014

  W is $57 (in ASCII). Make sure you are converting it properly before sending, I have to assume you are building that string with the checksum before sending it, and that is where it's going wrong. It's getting converted *again* somewhere along the line and getting sent out ASCII instead of hex. If I had to guess, I'd say you were using ITOHEX in building the final string. Don't, just tag it on like "<rest of string>, <checksum>". You don't have to convert anything for the actual command string.

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• tbell Posts: 10

  June 2014

  Thanks
  
  Thanks Guys!
  From the sound of it, I was over reacting to what I was "Seeing" in the send string in the output bar.
  I did send the string using the way you suggested Send_String dvPJ, "string,chksum" and it works for every other command that I have (inputs, power, etc.)
  Thanks for the clarification, and the cool trick!

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