Thanks for reply.
I mean four byte sequence after block title 0x3D and 0xD7.
Example(For sake of simplicity, complements removed):
Request:
07 01 D7 XX XX XX XX 03 (07 - block length, 01 - block counter, D7 - block title, 03 - block end)
Response:
07 02 3D YY YY YY YY 03 (07 - block length, 02 - block counter, 3D - block title, 03 - block end)
I need some definition of bytes XX and YY.