BCD in Delphi7

[Nikko Agustino]

Hello forums,

Currently I'm building an ACARS for my virtual airline. And I have a problem with BCD data from offset $034C, $034E, $0350, $0352, and $0354 which is shown as BCD. How can I store BCD data to delphi variable? I have searched on this forum and google but I can't find how to do it.

FSUIPC_Read($0354, 4, @xpdr, dwResult);  FSUIPC_Process(dwResult);
label2.Caption := FloatToStr(xpdr);
[/CODE]

If I use the above code it only show 0 on the label.

Regards,

Nikko

[Pete Dowson]

Currently I'm building an ACARS for my virtual airline. And I have a problem with BCD data from offset $034C, $034E, $0350, $0352, and $0354 which is shown as BCD. How can I store BCD data to delphi variable? I have searched on this forum and google but I can't find how to do it.

FSUIPC_Read($0354, 4, @xpdr, dwResult); FSUIPC_Process(dwResult);
label2.Caption := FloatToStr(xpdr);
[/CODE]

If I use the above code it only show 0 on the label.

I don't know Delphi at all, but I can immediately see two things wrong!

1. Offset 0354 is [b]2[/b] bytes long but you've set 4! Why?

2. The contents of 0354 is just a 16-bit value,[i] NOT [/i]floating point, so why try converting "FloatToStr"?

Declare "xpdr" as an integer, and set it to zero first.

After reading / processing, you can print it in hexadecimal, because the hex view of the value IS the transponder value. Each 4 bits is a digit, 0-7.

Pete

[Nikko Agustino]

Hi Pete,

Sorry for my mistake. I already change the code to integer value and the result is different from FS Interrogate value.

Here is the result for some squawk.

squawk result

1200 4608

2000 8192

7500 29952

7600 30208

7700 30464

I have no idea how to convert this. Or maybe I make another mistake to retrieve the value?

FSUIPC_Read($0354, 2, @xpdr, dwResult);  FSUIPC_Process(dwResult);
label2.Caption := IntToStr(xpdr);
[/CODE]

[Pete Dowson]

Sorry for my mistake. I already change the code to integer value and the result is different from FS Interrogate value.

Here is the result for some squawk.

squawk result

1200 4608 = 0x1200

2000 8192 = 0x2000

7500 29952 = 0x7500

7600 30208 = 0x7600

7700 30464 = 0x7700

Oh dear. I already told you, it is HEXADECIMAL!. I am sure Delphi has some way of converting a decimal number into a hexadecimal string!! Don't you have any reference books or "Delphi for Dummies" books to refer to?

If not you will have to resort to VERY simple arithmetic --

Take the Remainder when dividing by 16 = 4th digit

Take the Quotient from that and divide by 16, remainder = 3rd digit

Take the Quotient from that and divide by 16, remainder = 2nd digit

Take the Quotient from that = 1st digit

Try it!

Pete

[Nikko Agustino]

Hi Pete,

I'm sorry it's a misunderstanding here. I think the xpdr value is hexadecimal and need to be converted to integer. I was wrong, it was the opposite. And now the following code is fully working.

FSUIPC_Read($0354, 2, @xpdr, dwResult);  FSUIPC_Process(dwResult);
label2.Caption := IntToHex(xpdr, 1);
[/CODE]

Thank you very much Pete.

[Pete Dowson]

I'm sorry it's a misunderstanding here. I think the xpdr value is hexadecimal and need to be converted to integer.

The value is a 16-bit binary number. It is neither a decimal integer or an hexadecimal one, it is simply a row of 16 bits, each of which is 0 or 1. It is the way you interpret it, the way you display it, which changes, never the value itself which is still always a row of bits.

In the case of BCD, the hexadecimal way of showing it shows the correct Transponder code. It isn't the conversion of one type of value to another, only the way of showing it in printable/displayable form.

Pete