一段英文翻译(100分)

2.3.6 Two checksum bytes follow the ETX. The checksum is computed by taking the "2s" complement of the sum of the hexadecimal values of all the characters transmitted excluding the control characters (00 through 1F hex). Only the two least significant digits are used in the calculation. The value is sent in two ASCII digits.

看看我的翻译：

跟在[ETX]后面的是两个字节的CHECKSUM，CHECKSUM是除控制字符外所有字符以16进制相加再取补数（00-1F ？？？？？？），至少有两个字符参加运算。

问题是（00-1F）指的是什么？

00 through 1F hex 即值为 $0 - $1F 的控制符