/// <summary>Calculates the CRC16 check-sum on specified portion of a buffer.</summary>
/// <param name="data">Data buffer to perform check-sum on.</param>
/// <param name="startIndex">Starts index in data buffer to begin check-sum.</param>
/// <param name="length">Total number of bytes from <paramref name="startIndex">startIndex</paramref> to
/// perform check-sum over.</param>
/// <returns>Computed CRC16 checksum over the specified portion of the buffer.</returns>
public static ushort Crc16Checksum(this byte[] data, int startIndex, int length)
{
Crc16 checksum = new Crc16();
checksum.Update(data, startIndex, length);
return checksum.Value;
}
/// <summary>Calculates the CRC-ModBus check-sum on specified portion of a buffer.</summary>
/// <param name="data">Data buffer to perform check-sum on.</param>
/// <param name="startIndex">Starts index in data buffer to begin check-sum.</param>
/// <param name="length">Total number of bytes from <paramref name="startIndex">startIndex</paramref> to
/// perform check-sum over.</param>
/// <returns>Computed CRC-ModBus checksum over the specified portion of the buffer.</returns>
public static ushort ModBusCrcChecksum(this byte[] data, int startIndex, int length)
{
Crc16 checksum = new Crc16(ChecksumType.ModBus);
checksum.Update(data, startIndex, length);
return checksum.Value;
}