Reads one command of an application layer package.
A data fragment takes the whole message, as TS004-2.0.0 asks, and its bytes come back on data.
data
Which package: one of clock.PORT, fragment.PORT, multicast.PORT or firmware.PORT.
Whether the frame carrying it traveled up.
The message, from this command's identifier on.
The command that was read.
If the port names no package, the message ends inside the command, or the identifier is not one the package defines.
Reads one command of an application layer package.
A data fragment takes the whole message, as TS004-2.0.0 asks, and its bytes come back on
data.