In ASCII Protocol, each byte is a character. For example, if the byte sent was 0x35, it would be ASCII character 5.
In ASCII Hex Protocol, two bytes are used represent a single character. For example, if the device were to send 0x33 and 0x35, they would be combined as 0x35 (or the ASCII character 5).
In Binary Data Protocol, each byte is the sum of the bits that are set within. For example, for bits 00000101 set, the byte value would be 0x05. The decimal value would be 5.