checksum

[gmisk]

i need to calculate the checksum of a hex number from a text box.I had
already choosed the hex option from the pop-up menu but i need to know
how to find the checksum now.

[Nick Ryan]

Joirgos,
This is the code for the DOWCRC algorithm in VB. Hope it is of some use.

Function DOW_CRC_Algorithm(InputData, Output_Dec_Or_Hex)
'This is the array of data used in the DOW CRC algorithm. 0 - 255
'Data sent to this algorithm must be in the form of a hex string
'Data can be output from this algorithm in decimal or hexadecimal format
'The algorithm is recursive and will output one byte representing the
crc value
'of the data sent to the algorithm.
Dim DOW_CRC_Array
DOW_CRC_Array = Array(0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126,
32, 163, 253, 31, 65 _
, 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227,
189, 62, 96, 130, 220 _
, 35, 125, 159, 193, 66, 28, 254, 160, 225, 191,
93, 3, 128, 222, 60, 98 _
, 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192,
158, 29, 67, 161, 255 _
, 70, 24, 250, 164, 39, 121, 155, 197, 132, 218,
56, 102, 229, 187, 89, 7 _
, 219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165,
251, 120, 38, 196, 154 _
, 101, 59, 217, 135, 4, 90, 184, 230, 167, 249,
27, 69, 198, 152, 122, 36 _
, 248, 166, 68, 26, 153, 199, 37, 123, 58, 100,
134, 216, 91, 5, 231, 185 _
, 140, 210, 48, 110, 237, 179, 81, 15, 78, 16,
242, 172, 47, 113, 147, 205 _
, 17, 79, 173, 243, 112, 46, 204, 146, 211, 141,
111, 49, 178, 236, 14, 80 _
, 175, 241, 19, 77, 206, 144, 114, 44, 109, 51,
209, 143, 12, 82, 176, 238 _
, 50, 108, 142, 208, 83, 13, 239, 177, 240, 174,
76, 18, 145, 207, 45, 115 _
, 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180,
234, 105, 55, 213, 139 _
, 87, 9, 235, 181, 54, 104, 138, 212, 149, 203,
41, 119, 244, 170, 72, 22 _
, 233, 183, 85, 11, 136, 214, 52, 106, 43, 117,
151, 201, 74, 20, 246, 168 _
, 116, 42, 200, 150, 21, 75, 169, 247, 182, 232,
10, 84, 215, 137, 107, 53)

InputData = Remove_CrLf_Chars(InputData)
InputData_Len = Len(InputData)
DOW_CRC_Val = 0
For I = 1 To InputData_Len Step 2
InputByte = Mid(InputData, I, 2)
InputByte_Hex = "&H" & InputByte
InputByte_Dec = Val(InputByte_Hex)
New_Index = DOW_CRC_Val Xor InputByte_Dec
DOW_CRC_Val = DOW_CRC_Array(New_Index)

Next I


'Format the output from the algorithm
If Output_Dec_Or_Hex = "Dec" Then
DOW_CRC_Algorithm = DOW_CRC_Val
Exit Function
ElseIf Output_Dec_Or_Hex = "Hex" Then

DOW_CRC_Algorithm = FormatReceivedByte(Hex(DOW_CRC_Val))
Exit Function
End If


End Function
In article <39096F0E.82F1B1A8@hotmail.com>,
Jiorgos wrote:
> i need to calculate the checksum of a hex number from a text box.I had
> already choosed the hex option from the pop-up menu but i need to know
> how to find the checksum now.
>
>

--
Nick Ryan.
Test Engineer,
G14499@email.mot.com


Sent via Deja.com http://www.deja.com/
Before you buy.

[gmisk]

The solution is to use the mathematical function Eval Multi-Var Scalar and
as an argument of variables an array.The formula is X1+X2+X3..Xn.

Jiorgos wrote:

> i need to calculate the checksum of a hex number from a text box.I had
> already choosed the hex option from the pop-up menu but i need to know
> how to find the checksum now.