Why the call failed.
OptionaldataFor DataRate, the data rate.
OptionalformatFor a Format state, the format it was saved in.
OptionalmaxFor PayloadTooLong, the most the frame carries; for TooManyChannels, the most a device keeps.
OptionalstackOptionalstateFor State, why the saved state was not resumed.
OptionaluntilFor Wait, the earliest time to try again, in microseconds.
An error an end device threw, with what goes with its code.