DNC companies offered machine tool links using rugged proprietary terminals and networks.
No time was lost due to broken tapes, and if the software was correctly used, an operator running incorrect or out of date programs became a thing of the past.
As far as the control was concerned, it was receiving from the paper tape unit as it always had; in fact it was the BTR or Reader Emulation card which was transmitting.
With some exceptions, CNC manufacturers began migrating to PC-based controls running DOS, Windows or OS/2 which could be linked in to existing networks using standard protocols.
In some cases, users no longer needed a DNC "expert" to implement shop floor networking, and could do it themselves.
However, the task can still be a challenge based on the CNC Control wiring requirements, parameters and NC program format.
Instead of merely acting as a repository for programs, DNC systems aim to give operators at the machine an integrated view of all the information (both textual and graphical) they require in order to carry out a manufacturing operation, and give management timely information as to the progress of each step.
MTConnect is one prominent attempt to augment the existing world of proprietary systems with an open-source, industry-standard protocol using XML schemas.
Smaller facilities will typically use a portable PC or laptop to avoid the expense of a fully networked DNC system.