for i:=0 to a-1 do
begin
if(indata[i]=$f5)and(indata[i+1]=$0a)then
begin
if(indata[i+2]=$03)then
begin
for d:=i to a-2000 do
begin
if (indata[d
+3
]=$fa)and(indata[d+4]=$00) then
begin
y1:=indata[d+5]*256+indata[d+6];
y11:=FormatFloat('00.000',y1);
if TryStrToFloat(y11,c1) then
begin
iplot1.channel[0].AddXY(j/h,c1);
end;
inc(j);
end
else
if (indata[d+3]=$C0)and(indata[d+4]=$00)then
begin
y2:=indata[d+1];
y3:=indata[d+2];
y22:=FormatFloat('00.000',y2);
y33:=FormatFloat('00.000',y3);
memo2.Lines.Add(y22);
memo3.Lines.Add(y33);
end;
end;
end;
end
else
if(indata[i]=$f5)and(indata[i+1]=$0b)then
begin
if(indata[i+2]=$02)then
begin
for c:=i to a-1 do
begin
if (indata[c+3]=$fb)and(indata[c+4]=$00) then
begin
y4:=indata[c+5];
y44:=FormatFloat('00.000',y4);
if TryStrToFloat(y44,c2) then
begin
iplot2.channel[0].AddXY(j/h,c2);
end;
inc(j);
end
else
if (indata[c+3]=$C0)and(indata[c+4]=$00)then
begin
y5:=indata[c+1];
y6:=indata[c+2];
y55:=FormatFloat('00.000',y5);
y66:=FormatFloat('00.000',y6);
memo4.Lines.Add(y55);
memo5.Lines.Add(y66);
end;
end;
end;
end;
end;
end;

这么看好像没问题，你最好自己单步调试一下，看看每一步的局部变量是不是都正常。