[cesarsoftware]

Empezado por duilioisola

Podría tratarse también de un check de paridad como explican aquí: https://en.wikipedia.org/wiki/Longit...dundancy_check
Ten en cuenta que parece que al ser dos bytes de paridad deberías trabajar con WORDs y si el último byte del mensaje queda sin su par para generar un word habrá que resolverlo agregándole otro (por delante o por detrás) con valor 0.

Pseudocodigo byte
       Set LRC = 0
       For each byte b in the buffer
       do
           Set LRC = (LRC + b) AND 0xFF
       end do
       Set LRC = (((LRC XOR 0xFF) + 1) AND 0xFF)

Pseudocodigo word
       Set LRC = 0
       For each word b in the buffer
       do
           Set LRC = (LRC + b) AND 0xFFFF
       end do
       Set LRC = (((LRC XOR 0xFFFF) + 1) AND 0xFFFF)

Hola de nuevo
Muchisimas gracias, ya te has ganado unas el ultimo byte es LRC
Ya tenemos la mitad resuelta, ya solo falta la otra mitad, el byte anterior.

Pongo este código (por si lo quereis copiar) que incluye la función LRC en Delphi

Código Delphi [-]
procedure TPCVP.Button1Click(Sender: TObject);
var
  s: ansistring;
  // Longitudinal Redundancy Check
  function CalculaLRC(cadena: ansistring): word;
  var
    i: word;
  begin
    Result := 0;
    for i := 1 to Length(cadena) do
      Result := (Result + Ord(cadena[i])) and 255;
    Result := ((Result xor 255) + 1) and 255;
  end;
  // Longitudinal Redundancy Check
begin
  s := #144#130#0#1#58#49#144#3; //#245#239
  showmessage(IntToStr(CalculaLRC(s))); // = #239
  s := #144#130#0#0#144#3; //#248#91
  showmessage(IntToStr(CalculaLRC(s))); // = #91
  s := #144#130#2#6#144#3; //#248#83
  showmessage(IntToStr(CalculaLRC(s))); // = #83
  s := #144#130#0#1#58#50#144#3; //#245#238
  showmessage(IntToStr(CalculaLRC(s))); // = #238
  s := #144#130#0#255#6#144#3; //#246#86
  showmessage(IntToStr(CalculaLRC(s))); // = #86
  s := #144#130#1#5 +
       '45      ' + #0#0#0#0 +
       'COP     ' + #0#0#0#11 +
       'COPY    ' + #0#0#4#176 +
       'JON     ' + #0#0#0#0 +
       'ORIGTP10' + #0#0#0#0 +
       'TALATP10' + #0#0#3#252 +
       '        ' + #9#107#4#0 +
       #144#3; //#150#213
  showmessage(IntToStr(CalculaLRC(s))); // = #213
  s := #144#130#1#5 +
       '[**********PUNTA********' + #13#10 +
       'N1[ Pro/TOOLMAKER v9.0.030 ]' + #13#10 +
       'N2[ lunes, 31 de marzo de 2014 20:41:15 ]' + #13#10 +
       'N3[ V:\266\266ma01p.pun ]' + #13#10 +
       'N4[ Z:\08266\200\08266A_2002_P200_MACHO_1.dca ]' + #13#10 +
       'N5[ Eduardo Gutierrez ]' + #13#10 +
       'N6[ Trayectoria de herramienta sobre plano' +
       #144#3; //#195#140
  showmessage(IntToStr(Length(s) - 6) + ' ' + IntToStr(CalculaLRC(s))); // = #140
  s := #144#130#2#5 +
       ' de corte en Z 2 [35x6, 0.5] ]' + #13#10 +
       'N7[ Trayectoria de herramienta sobre plano de corte en Z ]' + #13#10 +
       'N8[ Thickness in XY is: 0.500 ]' + #13#10 +
       'N9[ Thickness in Z is: 0.500 ]' + #13#10 +
       'N10[ Cutter: 35.000x6.000 ]' + #13#10 +
       'N11[ Note: Cutter tip output ]' + #13#10 +
       'N12[ WARNING: Feedrate c' +
       #144#3; //#190#64
  showmessage(IntToStr(Length(s) - 6) + ' ' + IntToStr(CalculaLRC(s))); // = #64
  s := #144#130#3#5 +
       'ontrol cannot be used with Override Standard Feedrates - feedrate control disabled. ]' + #13#10 +
       'N13F P1' + #13#10 +
       'N14G0Z166.000' + #13#10 +
       'N15G0X308.605Y-103.414' + #13#10 +
       'N16G1Z144.827' + #13#10 +
       'N17F P2' + #13#10 +
       'N18X308.615Y-103.375Z144.430' + #13#10 +
       'N19X308.643Y-103.261Z144.050' + #13#10 +
       'N20X308.688Y-103.076Z14' +
       #144#3; //#199#137
  showmessage(IntToStr(Length(s) - 6) + ' ' + IntToStr(CalculaLRC(s))); // = #137
  s := #144#130#4#5 +
       '3.700' + #13#10 +
       'N21X308.749Y-102.827Z143.395' + #13#10 +
       'N22X308.823Y-102.525Z143.146' + #13#10 +
       'N23X308.907Y-102.181Z142.965' + #13#10 +
       'N24X308.998Y-101.808Z142.857' + #13#10 +
       'N25X309.178Y-100.910Z142.695' + #13#10 +
       'N26X309.283Y-100.000Z142.534' + #13#10 +
       'N27X309.310Y-99.085Z142.372' + #13#10 +
       'N28X309.261Y-98.170Z142.21' +
       #144#3; //#212#122
  showmessage(IntToStr(Length(s) - 6) + ' ' + IntToStr(CalculaLRC(s))); // = #122
end;

Lo único que no son 2 bytes, así que con un byte es suficiente.