Civil Engineering Reference
In-Depth Information
physical transmission medium (bus) is part of the standard. The defined data rate is
a bit rate of up to 1 Mbit/s.
ISO 11898-3:
Low-speed, fault-tolerant, medium-dependent interface
This stan-
dard was developed as part of Generalized Interoperable Fault-tolerant CAN trans-
ceiver (GIFT)/International transceiver conformance test (ICT) projects (see 9.2.3)
and also defines the functional and physical interfaces to the transmission medium
as well as the physical transmission medium. The data rate is defined up to a maxi-
mum of 125 kbit/s. The standard also specifies a fault management to implement a
fault-tolerant behaviour.
ISO 11898-5:
High-speed, medium-access unit with low-power mode
The standard
ISO 11898-5 is an extension of the standard ISO 11898-2.
The extension consists mainly in the description of the behaviour in the low-power
mode, or in the description of transitions between the possible modes of operation.
Implementations according to this standard (ISO 11898-5) can be used in conjunc-
tion with implementations according to the standard ISO 11898-2 in one network.
6.2.2
The Need for CAN Transceiver Testing
Section 6.1 has already given an introduction to the topic of testing. In this section,
this is specifically discussed and why it is necessary to test CAN modules and—as
part of them—CAN transceiver.
6.2.2.1
Use of CAN in Complex Bus Systems
Once bus systems were introduced in luxury automobiles, they have made their
way into all classes of vehicles in the automotive industry. Here CAN is the most
important and most widely used serial bus system. Almost every car today has at
least one CAN network on board.
CAN is used not only in automobiles but also in industrial control systems, con-
trol systems of ships, trains and airplanes, in plants of agriculture technology and
building automation, medical technology and renewable-energy systems.
The bus system is thus used in areas where high reliability and fault tolerance
are required. Within the bus system, CAN bus modules with different functions and
from different manufacturers are linked together via a common data line.
Those CAN bus modules have to work properly due to the application in safety-
relevant areas and meet all requirements which are placed on them. The require-
ments are defined in detail in the standard ISO 11898 (see Sect. 6.2.1). Core of the
specification is the data exchange between modules.
If each CAN module—irrespective of the manufacturer—which is involved in
a CAN network is compliant with the standard, it can therefore be assumed that
the components work together void of errors and the network as a whole meets its
duties.
