Convert A String To Get A Checksum?

Nov 30, 2011

I need to convert a string to get a checksum as follows;

Checksum

The checksum is the 8 LSB (least significant bits) of a simple addition of all octets (note that a message type '30' is two octets with the values 33 hex and 30 hex) following the STX character and until the checksum field. Note that all separators will be included in the checksum, but the STX, checksum and the ETX will not be included.

Dim str as string = "01/00064/O/30/12345678/87654321////////48656C6C6F20576F726C64/"

This should result in checksum = "C2" What type of checksum is this? what should I Google for? CRC, MD5, hash ?

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[Code]...

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''Public Function buildpacket(pdu As Integer) is what I want.
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[code]....

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For i = 0 To length - 2 Step 1
cksum += sendFrameData(i + 5)
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[Code]....

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[Code]...

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a line of hex bytes:

: 10 01 00 00 21 46 01 36 01 21 47 01 36 00 7E FE 09 D2 19 01 40

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[code]....

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Public Sub CreateLine(ByVal Data As String)
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[code]....

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