As far as I could understand, the deadline_timer just runs once, i.e., if I would like to use it multiple times, I have to instantiate new ones everytime.
That is not true. You can use expires_at or expires_from_now to reschedule an existing timer. Notice that any pending timeouts will be cancelled when you reschedule the timer. You have to call async_wait again after you reschedule the timer.
It needs to be turned on inside a separate thread, the command queue one, when it sends a serial command, and if the answer arives before the timer is due, it has to be turned off, again inside that separate queue thread, so it doesn't hit the "resend".
Use the cancel function to cancel the timer. Your handler function will still be invoked, but the error code will be "operation cancelled" instead of "not an error."
So far I did manage to put it to work, but after a few serial commands, some successful and some timed-out, the timer associated "service" crashes.
That sounds like a scope problem. The timer object must exist as long as there are outstanding handlers. ~Dan