106 lines
2.4 KiB
C#
106 lines
2.4 KiB
C#
using System;
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namespace MECF.Framework.Common.Utilities
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{
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public static class Crc16
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{
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private const ushort polynomial = 40961;
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private static readonly ushort[] table;
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public static ushort ComputeChecksum(byte[] bytes)
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{
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ushort num = 0;
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for (int i = 0; i < bytes.Length; i++)
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{
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byte b = (byte)(num ^ bytes[i]);
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num = (ushort)((num >> 8) ^ table[b]);
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}
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return num;
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}
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static Crc16()
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{
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table = new ushort[256];
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for (ushort num = 0; num < table.Length; num = (ushort)(num + 1))
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{
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ushort num2 = 0;
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ushort num3 = num;
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for (byte b = 0; b < 8; b = (byte)(b + 1))
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{
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num2 = ((((num2 ^ num3) & 1) == 0) ? ((ushort)(num2 >> 1)) : ((ushort)((uint)(num2 >> 1) ^ 0xA001u)));
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num3 = (ushort)(num3 >> 1);
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}
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table[num] = num2;
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}
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}
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public static ushort Crc16Ccitt(byte[] bytes)
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{
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ushort[] array = new ushort[256];
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ushort num = ushort.MaxValue;
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ushort num2 = num;
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for (int i = 0; i < array.Length; i++)
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{
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ushort num3 = 0;
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ushort num4 = (ushort)(i << 8);
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for (int j = 0; j < 8; j++)
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{
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num3 = ((((num3 ^ num4) & 0x8000) == 0) ? ((ushort)(num3 << 1)) : ((ushort)((uint)(num3 << 1) ^ 0x1021u)));
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num4 = (ushort)(num4 << 1);
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}
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array[i] = num3;
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}
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for (int k = 0; k < bytes.Length; k++)
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{
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num2 = (ushort)((num2 << 8) ^ array[(num2 >> 8) ^ (0xFF & bytes[k])]);
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}
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return num2;
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}
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public static ushort CRC16_CCITT(byte[] data)
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{
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int num = data.Length;
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ushort num2 = ushort.MaxValue;
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for (int i = 0; i < num; i++)
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{
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byte b = data[i];
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num2 = (ushort)(num2 ^ (b << 8));
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for (int j = 1; j <= 8; j++)
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{
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num2 = (((num2 & 0x8000) <= 0) ? ((ushort)(num2 << 1)) : ((ushort)((uint)(num2 << 1) ^ 0x1021u)));
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}
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}
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return num2;
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}
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public static ushort CRC16_ModbusRTU(byte[] bytes)
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{
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ushort num = ushort.MaxValue;
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int num2 = 0;
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foreach (ushort value in bytes)
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{
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num = (ushort)(Convert.ToInt32(value) ^ Convert.ToInt32(num));
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ushort value2 = 40961;
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while (num2 < 8)
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{
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if (Convert.ToInt32(num) % 2 == 1)
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{
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num = (ushort)(num - 1);
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num = (ushort)(Convert.ToInt32(num) / 2);
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num2++;
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num = (ushort)(Convert.ToInt32(num) ^ Convert.ToInt32(value2));
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}
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else
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{
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num = (ushort)(Convert.ToInt32(num) / 2);
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num2++;
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}
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}
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num2 = 0;
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}
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return num;
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}
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}
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}
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