How to Maximize the Availability of Your CNC Manufacturing

Summary

December 9, 2021 – Computer Numerically Controlled (CNC) machines play a vital role in countless manufacturing applications. They build these machines to process a variety of materials, such as metal and plastic, and shape them into the shapes required. Advanced technologies have also enabled CNC machines to become more powerful by offering more axes for greater precision and better operational efficiency. As CNC machines continue to evolve, they require more complex components, faster operating speed, and greater attention to machine operating condition to avoid system downtime.

Every second that a CNC machine in a factory is idle, offline, or shut down for maintenance translates into lost profit. Thus, the efficiency of CNC machines is very important to the results of a CNC automated factory. To improve productivity, plant managers need real-time information on the condition of their CNC machines. Usually one of three operational goals will shape your Machine Data Collection (MDC) strategy: to enable Distributed Numerical Control (DNC) communication of CNC machines to achieve remote management of recipe changes; Basic MDC to measure the overall efficiency of the equipment (OEE); and advanced MDC to perform predictive maintenance.

DNC communication

Many factory operators still operate legacy series CNC machines. To operate a modern production process, they have to generate the G code from the CAD / CAM software and manually upload it to the local controller (front PC) for manufacturing. This process is a very long and laborious operation. DNC software is often used to increase efficiency, making it possible to transmit recipes (G code) to multiple CNCs on a network, which also increases productivity.

Machine data collection

Machining equipment, for example, requires a large investment and only generates income when it produces parts. Machine Monitoring helps track non-productive machine time so you can improve machine utilization rates for better productivity. Traditionally, machine data was obtained manually at the end of the day. Often, this data can be entered incorrectly; thus, no preview can be obtained. To improve plant OEE, MDC software retrieves the necessary machine information from machines more accurately and quickly. Such requirements can also be met with DNC software if the CNC machines are equipped with serial or Ethernet network interfaces.

Whether you want to improve operational efficiency or improve the TRS of your machines, it is essential to enable smooth communication between your DNC / MDC software and CNC machines. Here are some Moxa connectivity suggestions you can consider.

Various connectivity requirements

Most unconnected CNC machines in factories are older legacy equipment that requires multiple communication interfaces to allow connectivity between CNC machines and DNC / MDC software. To update the G code on your serial CNC machines through the DNC software installed in Ethernet based systems, you need serial to Ethernet solutions deployed between the field sites and the control center. In addition, a growing number of engineers are striving to implement remote control of CNC machines using serial-to-wireless solutions, resulting in substantial savings in wiring maintenance and deployment costs. . For machine condition monitoring, you may need to collect information from existing equipment, such as light towers or cycle start / stop buttons, which would require the use of digital I / O solutions.

Communication performance is important

Data loss during DNC to CNC communications is unacceptable. Today, many older serial CNC machines only have a very small memory cache managed by a UART chip that is too small to hold a single set of instructions, which is often served by a tiny FIFO buffer. For these machines, download CAM instructions for a single, complex multi-step component. The limitations caused by small FIFO power supplies and slow serial connections add considerable time to data transfers, time that the DNC can better use to serve other stations. This is a significant problem for large factories, where DNCs are constantly uploading new G code files to CNC stations. Every slow CNC becomes a potential bottleneck, where a DNC could temporarily hang while waiting for a CNC to complete the data transfer. The reliability of data transmission is of the utmost importance in the workshop. You need a connectivity solution with a flow control mechanism to handle both sides of serial and Ethernet data transmissions, enabling serial to Ethernet communication with minimal transmission latency to download G code files on schedule.

Beware of cybersecurity

More than ever before, attention is focused on cybersecurity in industrial applications. Although CNC applications typically use closed network environments, more and more manufacturing networks are connected to the Internet, which introduces new types of cybersecurity threats. As a result, some level of protection will be required, such as password protection or account management, to limit authorized access to prevent unintentional or intentional intrusion into the network system. This type of protection can better ensure that operations will not be interrupted. For some specific types of manufacturing, such as aerospace components and medical components, production data is considered sensitive or confidential. In these cases, the edge devices used for data communication must be treated as a secure node and therefore must be well managed. Measures such as configuring account management for different types of user-level access, or even data encryption features to protect sensitive data, are also important.

Moxa has decades of proven expertise in providing reliable and easy-to-deploy connectivity solutions for system integrators and machine builders to develop their machine data collection applications. Learn more by downloading “Enable smart manufacturing with smart networking solutions”.