The driver is returning a hex encoded byte stream because it doesn't recognize the data type being reported by the PLC. You will need to parse the data and convert it to the type you want. The code would be similar to this:
Private Function ExtractINT(ByVal s As String) As integer
Dim bytes((s.Length / 2) - 1) As Byte
For i = 0 To (s.Length / 2) - 1
bytes(i) = Byte.Parse(s.Substring(i * 2, 2), System.Globalization.NumberStyles.HexNumber)
Next
Dim Result As Integer = BitConverter.ToInt32(bytes)
Return Result
End Function
I typed that code from memory and did not test it, so it may not be 100% correct.