Wired vs. Wireless
Instrumentation today is far more capable and advanced than just a decade ago.
Microprocessors continue to get more powerful and continue to reduce the power needed to perform tasks. However, the smart detectors and sensors today can operate reliably for years on a battery without any loss of performance. With wireless technology able to carry more information quickly, why would someone choose to install anything tethered to DCS anymore? Why aren’t battery operated wireless devices more common place? The answer is “it depends.”
First, not all instrument manufacturers have made the leap to lower the power usage on devices.
This could be driven by physical limitations of power hungry technologies, the decision to use the available power to do more like multivariable devices, or the perception that wireless technology is not secure enough yet or feasible. Whatever the reason, there are just as many products offered today that are wireless as there are wired.
Wired also continues to allow for more data and is still able to hold an edge on speed. With fieldbus, devices can send significant amounts of diagnostic data to AI algorithms and further push efficiency of operations. Also, the speed of wired solution makes wired the ideal choice for automatic safety instrumented systems. Wired options remain the mostly widely available offering, allowing customers to have multiple vendors for one solution. With wireless the control on price remains the alternative of using wired, but that shift to wireless is accelerating in many industries.
Wireless technologies bring a whole different calculation that make them very attractive.
Protocols like WirelessHART and ISA100 are eliminating hurdles of having multiple vendor support and security support. Without wires, companies can save hundreds of thousands of dollars on large projects. There is less trade off moving to wireless given it can also provide significant diagnostic information beyond just the primary variable. It is by far the most cost effective way to add instrumentation to an existing facility that is undergoing upgrades or expansion. Also, it can often be installed in locations where it is not practical to install wired detectors.
As the speed of response catches up to wired instruments, and confidence in the security and reliability of wireless instrumentation increases, we can expect more customers to move away from wired solutions. This will leave power and communications to more power hungry systems.