Convert large number to Binary for use in TCPIP socket project

[ballybeg]

Hey all,

I am working on a project that requires data transfer using TCPIP sockets. I am using a 3rd party Library (Ostrosoft) that handles the wsock32.dll api calls.

The project calls for the creation of a header that logs into a user account.

The first part of the header is a marker, with a value of 4,275,878,552. It is to be supplied in a Binary format of length 4.



My quesion is "How do I create this marker".

What I have tried so far is a string variable - strMarker thus:

strMarker = ChrB(&HFE) & ChrB(&HDC) & ChrB(&HBA) & ChrB(&H98)

Using the ChrB function to convert the Hex version of that number (FEDCBA98)

Any clues greatly appreciated.

ballybeg

[June7]

Does this help http://www.vb-helper.com/howto_net_binary_to_text.html

[ballybeg]

Thanks, It will help if it is not possible to do it in VBA, I will move to vb.net.

To provide a bit more data, here is the header with values I need to create:

Name	Length	Format	Value
Marker	4	Binary	4,275,878,552
MSN	2	Binary	0
Message Type	2	Binary	4096
Message Length	2	Binary	54
Action Code	2	Binary	4096
Error Code	2	Binary	0

In hex the result looks like this:

Header HEX
Start marker <4275878552> FE DC BA 98
MSN <0> 00 00
Message type <4096> 10 00
Message length <54> 00 36
Action code <4096> 10 00
Error code <0> 00 00

The final complication is message has to be submitted in network byte order!

Thanks
ballybeg



Perhaps this is too big a task for VBA to handle?

[June7]

Might be the number is just too large - beyond range of +/- 2147483648. http://windowssecrets.com/forums/showthread.php/49977-Convert-number-to-from-binary-(VBA)

I didn't notice link was .Net code but I expect could be modified for VBA syntax. The logic should be same.

This is a bit beyond my experience. What is "Binary format of length 4"?

[ballybeg]

You are correct in that the number is too large for a long in VBA.

The binary format length of 4 is four bytes which for the number 4275878552 = FE DC BA 98.

I know (via calculator) that 4275878522 = 11111110110111001011101010011000 binary, but I need to send the four bytes, so I have been using:

strMarker = ChrB(&HFE) & ChrB(&HDC) & ChrB(&HBA) & ChrB(&H98)

Which I figured should work, converting the four hex values to bytes, however I have not had much joy trying to create a login message.

thanks for the help anyway.

ballybeg

[June7]

This seemed relevant to your issue http://office.microsoft.com/en-us/ac...080764612.aspx

so I tried:

ChrB(&HFE) + ChrB(0) & ChrB(&HDC)+ ChrB(0) & ChrB(&HBA) + ChrB(0) & ChrB(&H98)+ ChrB(0)

the result is: þܺ?

Without the + ChrB(0) in each part I get: ??

and with:

Chr(&HFE) & Chr(&HDC) & Chr(&HBA) & Chr(&H98)

result is: þܺ˜