19 September 2016

MULTIPLEX SYSTEMS: DEBUNKING THREE “URBAN LEGENDS”

Just a few years ago, it was normal for a radio to be more or less the only electric component installed in a car. In today's vehicles, electric components account for roughly 35% of the overall value, and different producers are competing fiercely for onboard electronics, now considered a distinct advantage. Onboard electronics are interwoven with every function in a vehicle. They are no longer merely optional perks for comfort; they play in important role in managing energy efficiency, improving engine performance and guaranteeing the safety of a vehicle’s passengers. Today, a worksite vehicle can count on dozens of different ECUs (Electronic Control Units) that oversee practically every working element in the vehicle (engines, brakes, air conditioning and so forth). If every connection were created with a specific, dedicated cable, the overall number of connections (and therefore individual cables) on the vehicle would be enormous. In a situation like this, it’s easy to understand why the introduction of multiplex connections and communication BUSs have marked the start of a revolution. This apparently simple change has taken many years to spread around the world. And in many fields it has yet to achieve any clear consensus. Why? Digital keypads amount to a radical transformation of the dashboard, making the operator’s control panel more ordered and essential, and helping users manage complex actions in a simple, straightforward manner.There are a number of different reasons for resistance, but most of them lead back to three false convictions, or “urban legends,” concerning the use of BUS systems:

• “More electronics = more breakdowns. Traditional cables are more reliable because a breakdown in one cable only affects that particular line or command. In a BUS system this breakdown would compromise a number of different functions…”

This apparent reliability is a myth. The odds that a cable will break remain extremely low when compared with the probability of breakdowns in various different components and sensors. In this sense, a BUS system is more flexible, and makes it possible to quickly recover from non-serious breakdowns by distributing signals and commands in a different manner. A BUS system also improves diagnostics and functioning tolerance in active electromagnetic environments.

• “Electronics are expensive…”

Today’s components are mass-produced in volumes numbering in the millions of pieces. As a result, they cost much less than they used to. Recently, precisely in order to respond to economic issues like this one, companies have begun conceiving and realizing extremely simple BUS versions (CANopen) for which the cost of the components is extremely low. Furthermore, with a BUS solution it is easier to share information between different switchboards, sidestepping the need to install the same sensor in more than one system present in different areas of the vehicle. “A BUS system is complex, and incurs greater design and development costs…” Thanks to standardization for these solutions, this aspect has been turned on its head. Today it is far more simple to set up a BUS system. In fact, it is now possible to “simulate” a system of extremely complex devices by simply reproducing its behavior on the BUS. In this manner it’s possible, for example, to perfect and fine-tune a primary control panel. INNOVATION IS PHILOSOPHY, NOT A PRODUCT Discover our methods and stay cutting edge, subscribe to our newsletter