ACK (Acknowledge) is a character returned from the receiving machine to the sending machine to indicate that the preceding block of data are Ok.
ENQ must be something similar (but really I do'nt know)
This characters must be specified in the manual or you can test reading the port using low level functions (fgets() p.e) then you can break each character to know the value of this characters.
"Anyone who has never made a mistake has never tried anything new." A.E
"The important thing is not to stop questioning. Curiosity has its own reason for existing." A.E
