Firstly you need to divide the uplink payload into individual bytes (from left to right)
The 1st Byte is always Mode = it tells in what the device operates (List of modes)
The 2nd Byte is always Event = it tells what action triggered this message (e.g. short press, periodic report, breached the threshold, etc.) (List of events)
The 3rd Byte -
a. If the decimal value of 2nd Byte is lower than 128:
i. The 3. Byte is appended payload mask (Appended payload)
ii. The 4.–12. Bytes are the appended payload
b. If the decimal value of 2. Byte is higher than 127:
i. The 3.–12. Bytes are Event specific payload