0x05 - enquiry - enq
In computer communications, enquiry is a transmission-control character that requests a response from the receiving station[1] with which a connection has been set up.[2] It represents a signal intended to trigger a response at the receiving end, to see if it is still present. The response, an answer-back code to the terminal that transmitted the WRU (who are you) signal, may include station identification, the type of equipment in service, and the status of the remote station.
