A PSAS Message has a header with an ASCII four character code (e.g., ‘ADIS’) that identifies it. This is followed by a 6 byte timestamp in nanoseconds. This is always nanosecond since beginning of a program, which is usually the same as boot time for a device. This is followed by two bytes that give the size of the rest of the message. The remainder of the message is a collection of Data.
Data can be almost anything, even other messages. Usually it’s a pre-defined set of fixed sized numbers