It always seems like it’s the little things that often cause the most problems with your embedded system. The more I work with electronic systems, the more respect and care I have developed for cables and interconnect systems. This goes for projects at work, my home office, and simple repairs around the house.
As a new engineer, I was given the assignment of installing the first generation of computer terminals into police cars. I thought it was a pretty crummy job that was given to the “new guy.” Running power wires from the battery to computer system, data cables to the radio, and coax to the antenna seemed trivial. Why should someone with a master’s degree in EE be assigned this dirty and mundane job of crawling around and under a car loaded with electronics to hook up a few simple cables?
Guess what? If it is not done correctly, then nothing works! And if the installation is not done well, it won’t last long before strange and intermittent problems appear which can be traced back to poor connections. After my first installation of a small fleet of cars, I realized that this mundane job mattered greatly. It’s a life lesson every engineer needs to learn outside the classroom.
Cables are the lifelines of an electrical system. Cable reliability is based on both durability and signal integrity, and a cable system needs to withstand any environment in which it will be used, regardless of how challenging it may be. With embedded systems applications can include automotive, security, pipeline, military/aero, heavy industry, outdoor digital signage, and much more.
There is an interesting article in Electronic Products Magazine titled, The right cable system for your environment written by the WL Gore company. The article describes the advantages and disadvantages of typical materials used in cable construction, including an explanation of the testing and data analysis a manufacturer should perform in order to verify that its cable will perform in a specific application. The author also discusses potential factors can that affect the electrical performance of the cable system in an application. These factors include electrical performance, mechanical stress, environmental stress, and application-specific stress. These factors are interwoven and each has an effect on the other. Finally, he challenges the reader to consider all the elements of the total cost of ownership before selecting any cable system.
The bottom line is that there is a lot of technology involved with selection and specification of wire and cable for your system. Don’t just gloss over it. Consider both the impact of performance and the consequences of failure.