If you build machines for manufacturers or are in charge of operations at a manufacturing organization, saving time is an important way to stay ahead of the competition.
Saving time might mean:
There is a straightforward way to achieve these goals - move from passive wiring systems to active wiring systems. Not only does active wiring get machines into production faster, it increases operational availability and reduces the total cost of ownership.
Let’s take a look at passive wiring and active wiring to understand where and why time and cost savings occur with active wiring.
Active wiring speeds up building time for machines such as this tray erector. It also reduces start-up and makes it easier to fix problems, minimizing downtime.
Image courtesy: RML Engineering
Traditional passive hard wiring involves connecting sensors and actuators directly to the control system (PLCs) with separate cables. Running and terminating the wires is labor intensive and can be difficult in challenging factory environments. Using connectors streamlines the process somewhat so that cables can simply be plugged in, allowing the system to be built in a temperature-controlled workshop.
Another approach is to connect sensors and actuators via passive input/output (I/O) modules and common power lines, making installation a little easier. Cables can be pre-assembled with standardized M12 or M8 connectors, reducing installation time. This method has the advantage of allowing digital or analog signals to be transmitted and read.
The biggest limitation of passive wiring is that as a machine or system gets larger, the wiring becomes exponentially more complicated. A large system can have many cable connections, making it very time intensive and expensive to install and reconfigure.
Active wiring enables high-speed, bi-directional data communication, allowing sensors to monitor themselves, store data and send alerts of possible failure points. For example, status messages on the contamination level of sensors and actuators, their operating temperature, and the number of switching cycles, can be transmitted and evaluated.
There are two approaches to active wiring:
Keeping the wiring outside of the control cabinet expedites the wiring process and reduces the number of cables entering the cabinet. The quick-disconnect cord sets also provide for easy termination.
Therefore use active wiring for:
Distributed I/O modules are available with high protection ratings of up to IP69K, meaning they can be used in many harsh environments. For example:
The automotive industry employs active wiring with distributed I/O almost exclusively. The powertrain engineers responsible for building transmissions and engines, and the body and assembly workers, are big proponents of this technology. They realize the benefits of this approach every day.
The automotive industry relies on active wiring with distributed I/O. Faster installation, easier troubleshooting and reduced downtime are the reasons why.
Unless you are dealing with a small system today, the benefits of active wiring surpass those of passive wiring.
Active fieldbus I/O modules, combined with pre-tested terminators and double-ended cordsets, dramatically decrease the amount of time it takes to wire machines. The machine wiring time can be reduced from hundreds of hours to just days, not to mention making the machine easy to reconfigure and troubleshoot. Not only does this save time during the initial build at the machine builder facility, it reduces time to production start once delivered to the customer site.
Another advantage is that this approach reduces the number of potential mistakes made in the process. And, after the setup process, if something happens to be damaged, the control panel does not have to be opened nor the entire system shut down to fix it.
All in all, there are many good reasons to consider active wiring with distributed I/O for your application. When doing so, be sure to evaluate the initial higher investment in I/O modules and cordsets versus the savings in machine or system wiring costs and reduced downtime. Additionally, consider the opportunity for higher revenue or improved competitiveness from faster machine building and faster production start-up time.
Are you considering active wiring for your new projects? Why or why not? I look forward to hearing from you.
This article was written with expertise from Tim Senkbeil, a product line manager for Belden’s Lumberg Automation brand and Dr. Thomas Schoepf, director of R&D for connectivity products.