!7PWR00 != 2D 1F 00 04
!7PWR00 = 21 37 50 57 52 30 30

Take a look at ASCII, HEX, and binary encoding schema. All three have characters that are equivalent to each other.

[Link: en.wikipedia.org]
[Link: en.wikipedia.org]
[Link: en.wikipedia.org]

21 hex = ! ASCII and so forth.

Once you understand the schema a bit the protocol manual is easier to figure out.