If 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 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. Several vendors in our industry market proprietary multiplexing products. And almost every vendor with an electronically controlled product has had to wrestle with the communications between their product and its control panel. In fact, many RVs have as many as a half-dozen of these component-specific panels installed.
Standalone controls offer no new capabilities to entice the RV designer. Adopting RV-C does not mean that a standalone control panel can't be offered. In fact, using RV-C as the protocol for a standalone display is costs very little more than using a conventional point-to-point method such as RS-232. Nothing is lost in adopting RV-C - the product can still be marketed and installed in the conventional way.
But introducing a new proprietary protocol into the market would be a huge gamble for any company, and would almost certainly fail. It goes without saying that RV manufacturers are less than enthusiastic about adopting proprietary solutions and accepting the vendor lock-in they create. Such a network would have to have some truly compelling features to be viable in the current market. Adopting another vendor's protocol would be a similar gamble – will that vendor's protocol be more successful than the efforts of the entire industry?
Not surprisingly, 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. The RV manufacturers are in a similar state: some have dedicated staff time to their implementation, others are still exploring. RV-C is the safe bet for both vendors and manufacturers who want the benefits of multiplexing.