Civil Engineering Reference
In-Depth Information
data link layer and physical layer are set according to the ISO reference model
ISO/IEC 7498-1. The “High Speed” CAN bus access (up to 1 Mbit/s) is speci-
fied in ISO 11898-2 and mainly used in the propulsion of a vehicle. The “Low
Speed” CAN (40…125 kbit/s) for the comfort section is described in ISO 11898-
3. ISO 11898-4 allows a time-triggered communication to ensure a smooth data
transfer with high communication traffic. Available since 2007, the expansion of
the ISO 11898-2 describes the behaviour of a CAN high-speed node in the power
saving mode. Since the early 1990s, CAN was at first used in series-production cars
and also in industrial control, usually in conjunction with the higher CANopen pro-
tocol. CANopen (see Sect. 6.1) is specified in the European standard EN 50325-4
and is maintained by the user organization CiA (CAN in Automation). Reasons for
the series use are certainly the high performance standard, low costs and the wide
range of semiconductor manufacturers, which offer CAN modules. CAN was used
first in the Mercedes S-Class in 1992 and served there as a high-speed network for
communication between engine control, transmission control and dashboard. A sec-
ond CAN network was—at low speed—used for distributed climate control. BMW,
Porsche, Jaguar, etc., put CAN into series-production cars shortly after.
Typical applications of CAN are:
• Transportation with CAN applications: passenger cars, trucks, planes, trains,
ships, agricultural machinery, construction machinery, etc.
• Industrial control automation technology with CAN communications such as:
programmable controllers, automatic handling equipment, robots, intelligent
motor controllers, intelligent sensors/actuators, hydraulic systems, intelligent
meters for different applications such as water consumption, energy consump-
tion, etc., textile applications such as spinning, weaving, etc., medical techno-
logy, laboratory automation, building systems, elevators, automatic teller machi-
nes (ATMs), toys, mechanical tools and much more.
Nowadays, it is increasingly important, also through the tightening of legal regula-
tions, to reduce CO
2
emissions and fuel consumption of new vehicles. At the same
time, with shorter development times, the driving performance and the comfort of
a vehicle are to be increased, costs reduced and quality improved. Thus, there are
always new challenges to the development of electronic systems in vehicles; some
of them are only possible by a high degree of networking. Many of today's standard
techniques would not be feasible without the use and dissemination of field buses.
1.1.1
Standardizations of CAN
Robert Bosch GmbH began as an electronic control unit (ECU) manufacturer in
1983 with the development of a communications protocol for bus systems, which
was initially only intended for the use in the automotive sector. The result was
CAN. The first CAN chip was offered to car manufacturers in the late 1980s by In-
tel. CAN was finally standardized in November 1993 as ISO 11898
Road vehicles—
