哪种算法用于计算校验和？

Question

我正在尝试破译几个 HVAC 控制器之间用于 RS485 通信的协议。正如您在下面的列表中看到的那样，我能够识别单个消息。

00020003400012A9
00030103400012A7

00010303400012A7
2001030A400012010104FFFFFFFF7E

00010303400016A3
200103094000160C0C010400441C

000103074100000024A003ED
2001030A4100000024A0030895BA73

0001032A90020030000200310700013000020131070002300002023107060330000203310700043000FF053000FF1F
2001030290004A

00020003400012A9
00030103400012A7

00010302D10227
20010312D140200100002101000022010000230100002F

00020003400012A9
00030103400012A7

00010302D20226
20010302D240C8

00020003400012A9
00030103400012A7

00010302D10227
20010312D140200100002101000022010000230100002F

00020003400012A9
00030103400012A7

00010302D20226
20010302D240C8

00020003400012A9
00030103400012A7

00010302D20226
20010302D240C8

00020003400012A9
00030103400012A7

00010302D20226
20010302D240C8

00020003400012A9
00030103400012A7

00010302D20226
20010302D240C8

每行包含一个十六进制格式的完整消息。我认为最后一个字节（最后两个十六进制字符）是先前数据的校验和，但这只是我的猜测。

使用哪种算法计算此校验和？

Answer 1

我现在发现了算法。它只是汇总数据并构建某种 2s 补码。这是一个例子：

data: 0x20010312D14020010000210100002201000023010000

binary sum: 1 1101 0001 (0x1D1)
last byte:    1101 1110 (0xD1)
invert:       0010 1110 (0x2E)
add 1:        0010 1111 (0x2F)
use only last byte of calculated CS

CS: 0x2F

哪种算法用于计算校验和？

Which algorithm is used to calculate checksum?

protocols

checksum

serial-communication