IXXAT CAN Topology Products

CAN Repeaters

Repeaters are used to establish the physical coupling of two or more segments of a CAN bus system. They can be used to implement tree or star topologies as well as long spur lines. In addition, network segments can be electrically decoupled using a galvanically isolated repeater.

The lines coupled by the repeater are independent electric segments that can be optimally terminated in terms of signals. In this way topologies can be implemented that are not possible with a pure line of the bus due to electrical reflections.

The division of a CAN system into several subsystems connected via CAN repeaters also allows the maximum number of bus subscribers defined by the transceiver output capacities to be increased.

As messages are not addressed in CAN, the repeater logic has to translate the signals of the segment received into the other signals in each case and ensure that the input signals are not back-coupled. In terms of signals, the repeater corresponds to a line with relevant delay time. It cannot therefore be used to extend a CAN system.

Using repeaters does not influence the real-time behavior of a system, because in terms of transmission behavior it corresponds to a network that only consists of lines.

Another area of application of repeaters is the coupling of different physical CAN layers, e.g. by means of high/low-speed repeaters or optical repeaters.

The repeaters offered by IXXAT have an additional monitoring function. Connected network segments that are disturbed by permanent dominant levels, are detected and automatically disconnected, thus enabling the remaining network to continue functioning normally. After the fault has been eliminated, the operation of a disconnected segment is detected and the segment can automatically be reconnected to the network.

IXXAT also offers the repeater technology for licensed integration in customer hardware.