According to WhatIs.com, noise can be defined as “unwanted electrical or electromagnetic energy that degrades the quality of signals and data.” Noise can affect the performance of apparatus installed in parking facilities such as payment terminals, guidance systems, and the like.
Occuring in both digital and analog systems, noise can affect electronic transactions of all types, including text, programs, images, audio, and telemetry. Noise can be a more significant problem in wireless systems than in hard-wired systems. In general, noise which originates from outside the system is inversely proportional to the frequency, and directly proportional to the wavelength.
What kind of impact does noise have on our payment terminals? On our parking payment apps? And what must we consider when installing parking management systems?
It’s important to be able to identify potential sources of noise interference. And there are three main culprits:
- Electrical noise
- Radio noise (RFI)
- Magnetic noise
Electrical noise is caused by surrounding electrical apparatus resulting in a fluctuation of current and voltage in the operating machine. Electrical noise can be classed as thermal, shot, flicker, burst or transit time. Interruptions in the current as it travels through the circuitry connecting the devices hinder the communication between hard and software. How can we avoid this happening?
- Ensure the ground wire is properly earthed
- If possible, keep the apparatus on its own electrical circuit
- Ensure wiring is kept away from anything that may emit a signal, such as fluorescent lighting, barrier gates, cameras or guidance systems.
Radio noise (Radio Frequency Interference)
If your device uses radio signals to transmit information across particular frequencies, competing signals can cause quite some interference. Here are a couple of tips to help prevent transmission delays.
- Install antennae securely on the outside of the apparatus.
- Maintain a distance of at least 20cm between multiple antennae.
A.k.a the Barkhausen effect. The amount of magnetic noise created in urban areas is so widespread that it can disrupt the magnetic compass orientation of migratory birds. So how can we avoid it disrupting the smooth traffic flow?
- Keep a safe distance between apparatus. Ensure each machine has the room to operate effectively utilising its own communication devices.
- Place wiring away from the source of the magnetic fields. Avoid placing signal cables in proximity to power cables and heavy electrical equipment.
Another overall approach to avoiding noise interference is to use fiber optics, a technology far less susceptible to noise.
Is this a recurring problem for your engineering teams? How has your company overcome it? We'd love to hear your feedback...