SAS CRC algorithm C# .NET

[JonaMX]

Does anyone has the CRC SAS algorithm ??

I don't know how to implement in C# the one that includes IGT SAS 6.02 document  (attached picture) 

[zarobhr]

i hvae one that works in c#i will have to post itfrom the other pc

[JonaMX]

i hvae one that works in c#i will have to post itfrom the other pc

thanks I'll waiting it

[zarobhr]

here you go i use this to both compute the crc when sending commands and to compute the crc on recieved data to make sure the recieved crc is valid
in order for  this to work the byte[] cannot include the crc bytes

Code:

public  static byte[] ComputeCRC(byte[] val)
        {
            long crc;
            long q;
            byte c;
            crc = 0;
            for (int i = 0; i < val.Length; i++)
            {
                c = val[i];
                q = (crc ^ c) & 0x0f;
                crc = (crc >> 4) ^ (q * 0x1081);
                q = (crc ^ (c >> 4)) & 0xf;
                crc = (crc >> 4) ^ (q * 0x1081);
            }
            return new byte[] { (byte)(crc & 0xff),(byte)(crc >> 8) };
            
        }

Moderator: I enclosed your code in an SMS code block, because the command  "c = val [ i ];" was interpreted by the forum software as an italic command. SF

[JonaMX]

here you go i use this to both compute the crc when sending commands and to compute the crc on recieved data to make sure the recieved crc is valid
in order for  this to work the byte[] cannot include the crc bytes

public  static byte[] ComputeCRC(byte[] val)
        {
            long crc;
            long q;
            byte c;
            crc = 0;
            for (int i = 0; i < val.Length; i++)
            {
                c = val;
                q = (crc ^ c) & 0x0f;
                crc = (crc >> 4) ^ (q * 0x1081);
                q = (crc ^ (c >> 4)) & 0xf;
                crc = (crc >> 4) ^ (q * 0x1081);
            }
            return new byte[] { (byte)(crc & 0xff),(byte)(crc >> 8) };
           
        }

Thanks zarobhr I'll use it and comeback to tell you how it works

[JonaMX]

It works pretty well thanks again zarobhr 

[StatFreak]

It works pretty well thanks again zarobhr 

Thanks for letting us know.    I'm assuming that you found the little glitch in the code displayed in the post, which I just corrected.
I noticed that your original code was using the value 17d, instead of 15d, which is equal to 0x0f.


Stat

[zarobhr]

aw is that the icon that looks like a # sign

[StatFreak]

aw is that the icon that looks like a # sign

Yes it is. As you can probably tell, it doesn't get much use around here.
BTW, I gane you a  too.

[zarobhr]

aw is that the icon that looks like a # sign

Yes it is. As you can probably tell, it doesn't get much use around here.
BTW, I gane you a  too.

thanks

[JonaMX]

It works pretty well thanks again zarobhr 

Thanks for letting us know.    I'm assuming that you found the little glitch in the code displayed in the post, which I just corrected.
I noticed that your original code was using the value 17d, instead of 15d, which is equal to 0x0f.


Stat

Yeah in fact it is

c=val[ i ];

Not c=val;
 

[StatFreak]

Well, you wouldn't have much of a recursive "For/While" loop if there were no "i".     

[stayouttadabunker]

I gave all you guys a + Karma! 
Great little thread!