CAN Bridges and Gateways
CAN bridges and CAN gateways are infrastructure
components with which complex network structures can be implemented.
CAN bridges can connect CAN networks of
different bit rates or protocols with each other. They are based on the
store-(modify)-forward principle, where CAN messages are received by a
sub-network and then transmitted in the other sub-network.
Translation and filter rules can also be used,
by means of which, for example, a protocol adaptation can be carried out
between the sub-networks. A bridge can therefore also provide simple
Compared to the CAN repeater, the CANbridge
enables the enlargement of the maximum network size, so that the
sub-systems work fully self-sufficiently with regard to bus arbitration.
CAN sub-networks connected by bridges are independent of each other in
terms of their real-time behavior and are to be regarded as independent
CAN-bridges are suited to creating hierarchical
networks by transferring only the information to the connected sub-network
via bridges which are relevant for the sub-network. The bridge function
can be executed with the aid of other transmission systems. For example,
the CAN-Ethernet-CAN bridge is connected via two Ethernet-TCP/IP gateways
which enable connection to remote CAN networks.
As an extension to the CAN bridges, CAN gateways
enable access to CAN networks via other communication systems. The
protocols of the connected bus systems are mapped in the other
communication model in each case.
In this way, for example, devices with only one
serial port can be connected to CAN/CANopen networks via CAN/CANopen-RS232
gateways. Gateways can also provide remote accesses to CAN networks. The
CAN-TCP/IP gateway, for example, thus enables worldwide access to the CAN
network, e.g. for diagnosis and service purposes.