What is DNC software for manufacturing?
DNC refers to Direct or Distributed Numerical Control and is a vital building block for true Industry 4.0 and IIoT (Industrial Internet of Things) integration for machine shops.
In its most simplistic form DNC software and systems take over where CAM (Computer Aided Manufacturing) leaves off. While the CAM software is used to create the the NC file (also called G-code) for a particular CNC (Computer Numerical Control) machine, the DNC software is used to get the code from programming to the shop floor.
Most CNC machines on the shop floor have sufficient memory or hard drive space to store a NC file locally at the machine and execute the file to make a part. DNC systems provide a central repository on a computer or application server to both store the approved NC files for download to the shop floor and act as a gatekeeper for revision control regarding this G-code.
The main purpose of DNC software in today’s smart manufacturing environment is to create a software interface and base system for accountability and control of data (including NC files) to and from the shop floor. It must be 100% reliable, as it is a corner stone for building the important connection needed between the shop floor and the top floor.
If a shop is using hardware such as USB memory sticks, floppy disks, PCMCIA cards, roving laptops, paper tape or any other ‘sneaker ware’ transfer medium, then it needs to invest in a DNC system to start the journey of increased productivity and time savings.
How does DNC software connect to my CNC machine tools?
The connection from the Engineering department or CAD/CAM programming computer is accomplished though shop floor networking and typically is managed by an IT department. This connection could be either wired or wireless to the actual equipment and, based on the age of the CNC machine, could be either Ethernet or RS232. Most IT policies separate the CNC network from the shop floor network though what is called a VPN (Virtual Private Network) that may bridge these two different systems.
How do DNC systems handle NC file transfers?
DNC software contains the ability to view, edit and backplot G-code depending on what user rights are setup. The software also allows for one of the most important features commonly referred to as ‘Remote Request’. Using this feature, programmers will store NC files available for the operators of the CNC machines to call or download to the shop floor at their convenience and work schedule.
This call for the NC file commonly happens with a small file resident in the control of the CNC machine and may look similar to this:
% O0001 (Request Program) (*GET-)(AIRFOIL1234-20-A-C-19.NC) M30 %
In this example the operator is calling for a NC file from programming that has a drawing name of AIRFOIL1234, an Operation of 20, drawing rev A, tape rev C, was programmed and post processed for machine type 19.
Other ways to initiate file transfer to and/or from the shop floor may involve a machine operator using a shop floor terminal, tablet, or even a shop traveler and a bar code scanner.
What features should I look for when choosing a DNC solution?
When choosing a DNC software provider, look for one that can scale with your business. Make sure that the interface is fresh, relevant, and can accommodate not only the new CNC machines that are being connected, but all of the legacy equipment that needs to have a reliable serial to digital connection as well.
While looking at options, determine how connected the DNC software is to the CNC machine monitoring software or platform. Ask about Open API (Application Programming Interface) ability and what the time schedule for new release enhancements is. Also look at what type of lean management principles can be built upon and what quality approaches can be tracked.
How does DNC interact with my ERP, MRP, or other manufacturing software solutions?
The best evolved DNC systems have been integrated for machine monitoring and link to the ERP (Engineering Resource Planning) or MRP (Material Resource Planning) system through what is called a MES (Manufacturing Execution System). These systems are aware of not only the plan for the shop floor but what is happening historically and live with real-time data being collected.
In many cases the operator will see the next job scheduled for a CNC machine on a local tablet at the work center and will call for the NC file at the appropriate time during job setup. If for any reason this NC file had to be modified during production, then the file can be uploaded back to the DNC central inbox for that machine and changes can be reviewed at a programmer or engineering level.
These evolved DNC systems allow all other levels above them to provide additional Industry 4.0 projects and enhancements. With a ‘Connected Shop Floor’ a true smart manufacturing environment can exist. Data can flow in between the machine and people on the floor and all other departments within an organization. The transparency of operations and the power of real time data transforms a company and the people within it to a whole new level. Big Data, Machine Learning, Digital Twins, AI, Dynamic Finite Scheduling, and a host of other science can not prosper without the fundamental connection being made with a DNC system and the software that orchestrates it.
What other manufacturing solutions should I be exploring?
While the DNC system may be a first step, realize that you are on a path of change for the shop floor. Understand that there is a human element that also need to be addressed with both machine connectivity and production monitoring.
The pathway will change the way you look at and interpret data to make informed decisions and also the way people actually work within a factory environment. Finally, embrace the 4th Industrial Revolution and let it empower your organization to move into the increased mindset of constant improvement.