f Multiplexing means allowing electronic devices to talk on the same wire, using the same language, then RV-C is simply the description of the wire and the language. There are multiplexing protocols defined for cars, tractors, factories, and aircraft. RV-C is simply a protocol designed specifically for RVs, and supported by major RV manufacturers and component vendors.
RV-C is based on a protocol called “CAN”, or “Controller Area Network”. Developed by Bosch GmbH in the 1980s primarily for the automotive industry, CAN has become the basis for protocols used in all kinds of vehicles. Virtually all cars built in Europe, and a great many built in America, include a CAN network that connects the engine, transmission, anti-lock brakes, and instrument panel.
CAN is the steel girders from which RV-C is built. The rest of the structure is the work of the RVIA Technical Subcommittee for Multiplexing Electronics. Formed by the RVIA in 2001, the committee membership includes representatives of over two dozen leading RV builders and suppliers. The committee began its work by selecting CAN as the basis for RV-C, favoring the technology for its reliability, low cost, and wide availability of chips and tools. Since then, the committee has labored for two years to define the rest of the “language”.
The result of their work is a document available to the public through the RVIA. The essential elements of the work are complete, but just as the English language continually adds new words, RV-C will continually expand to include novel devices and new technologies. Ultimately, the process of maintaining and expanding the language will become the job of ANSI, the American National Standards Institute, with the close participation of the RVIA and its members.
There are alternatives to RV-C. RV manufacturers today can choose from several proprietary multiplexing systems, or they can build their own multiplexing systems by customizing components themselves. But RV-C is a far more effective way to get the best advantages of multiplexing.
Alternative systems cannot provide the full benefits of multiplexing. Although they typically can control coach systems, they cannot interface with the existing electronics and provide meaningful diagnostics. The monitoring options available are usually far less than with RV-C. Service and diagnostic procedures are not standardized. And the total system costs are rarely competitive.
But perhaps the most troubling problem with alternative systems is the inevitable vendor lock-in. The choice of a proprietary system vendor is a difficult choice to change. And the network limits the manufacturer's choices for other components – generators, inverters, tank sensors, et cetera – or force them to sacrifice functionality. The RV builder is doubly troubled.
But with RV-C, there is no network vendor – the network itself is in the public domain – and the manufacturer may choose components from any vendor participating in the RV-C effort. Already a large number of major vendors have announced products or otherwise indicated their intention of supporting RV-C in their products. And many others are simply waiting for the market to develop. Since RV-C is fairly inexpensive to implement and specification is publicly available, RV manufacturers can be sure to have plenty of choices for all kinds of components in the near future.