The beauty of single-point control systems

Feb. 10, 2014
CMD Adopts Many Control System Technology Improvements, but None Have Been as Beneficial as Industrial Ethernet Networking
About the Author

Mitchell Hein is an electrical engineer at CMD, Appleton, Wis., a builder of plastic converting machinery and automation, and a growing supplier of CNG refueling equipment.

For more than 25 years, CMD has provided high-speed converting equipment to the plastic film industry. In that time, we've adopted many improvements in technology that were directly applicable to our control systems. From servomotors and high-resolution color, flat-panel operator displays to high-accuracy ultrasonic sensors and high-speed PLCs, technology has made it possible to increase speed, reliability and function, often without adding cost. However, few things have provided such a significant benefit as industrial Ethernet networking.

Film-converting lines always have consisted of two to four independent machines. Converting lines traditionally used hardwired analog speed signals to communicate the speed of the film web among those machines. With the advent of industrial Ethernet, the functionality and flexibility of network connectivity quickly replaced the 0- to 10-V signal.

SEE ALSO: Nothing but Growth for Ethernet

Where the old system had issues with bias and noise, the new Ethernet network allows every CMD machine to follow a digital value, a system which has far greater accuracy, repeatability and responsiveness than the old analog line could ever hope to match. But that was only scratching the surface. Once the network link was in place for sharing the speed signal, it was obvious that it could do so much more.

To improve our customer's productivity, CMD developed a system to track product quality issues through the line and cull out only the product that was defective. This system passed the information from machine to machine on the network, with each machine using the information to its benefit. CMD also developed a common alarm history system, which allowed a machine operator to view the machine status of any machine from one operator terminal. By consolidating all the information needed in one place, an operator could spend far less time running between machines, and more time monitoring the line and optimizing its efficiency.

The success of that single-point control model led to the next efficiency improvement. Once we saw how much more efficient it was for a single machine operator on a production line, it wasn't long before we realized that each production line could be combined into a single plant network with the ability to track production, view status and provide a birds-eye view of the entire production floor.

For CMD and for our customers, industrial networking ushered in the age of modern film converting — and the story doesn't end there.

Over the past several years, CMD diversified its business model into new industries. As a result, we currently build fast-fill, compressed natural gas (CNG) systems. These compression and dispensing systems provide fuel for trucking fleets that converted from diesel fuel to CNG, which is significantly more economical and environmentally friendly.

Unlike bag- and pouch-converting equipment, the CNG filling sites are not a collection of machines in one building. Individual sites are spread out across the entire country. This presents a logistical challenge when one considers that you can't afford to have a person at every site 24/7 to ensure that the system functions as expected. Once again, our single-point control model seemed to be the correct approach, but we no longer could use a single hardwired plant network to provide the backbone for our system.

Enter the Industrial Ethernet Router solution from eWon. This device lets us establish a VPN connection from our machine to anywhere via the Internet, and it can be configured to send out emails with status and alarm information. The router seamlessly communicates on our local area network with our PLC, and allows remote connection from anywhere with a simple laptop.

The router allows you to create graphical, HTTP-based web page screens that can be accessed to show current system pressures and temperatures. Software updates and corrections can be rolled out to the controller at each site without sending a service person to that location — a benefit that reduces servicing costs and increases speed of response. A single service technician at a computer workstation can monitor the current operating status of every system installed in the country. If he can't correct a situation himself, he can act as a dispatcher to local service contractors, who can take care of actual mechanical maintenance.

The advent of industrial networking for machine control systems has given birth to this new single-point control method, which saves money, provides a real value to our customers, and gives us a competitive advantage.