Waits for some aspect of the state of a serial port to change.
wait-serial-port-state serial-port keys &key timeout => result
A serial-port object.
A list of keywords.
wait-serial-port-state waits for some state in the serial port associated with serial-port to change.
The argument keys should be a list of one or more of the keywords
result is a list giving the keys for which the state has changed.
If timeout is non-nil then the function will return
nil after that many seconds even if the state has not changed.
LispWorks User Guide and Reference Manual - 20 Sep 2017