DNC or file transfer between PC and CNC DNC or file transfer between computer and CNC Control. We offer ConnectCNC as an alternative to the very powerful, but very expensive DNC programs designed to service many machines at a time. You can use ConnectCNC for any number of machines, but transfer or DNC capability is one COM port at a time. Note that each of the CNC controls in your shop can have its unique configuration and port designation. Try ConnectCNC free for thirty days.