CANopen
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Network Architecture
WAGO-I/O-SYSTEM 750
CANopen
4.2.3 Network Topology
To build a simple CANopen network, you need a master (PC with a CANopen
fieldbus PCB card), a connection cable and a DC 24 V power pack to ensure
the power supply in addition to a CANopen fieldbus node.
The CANopen network is constructed as a line structure with matching resis-
tors (120 Ohm).
In systems having more than two stations, all subscribers are wired in parallel.
The maximum length for a conductor branch should not exceed 0.3 m.
Terminator
Terminator
Line, Bus
Terminator
Network node
Fig. 4-4: Bus topology of a CANopen network
g012430e
All net subscribers communicate at the same Baud rate. The bus structure
permits coupling in and out without side effect of stations, or the step-by-
step start-up of the system.
Later extensions have no influence on stations already in operation. The
system automatically detects when a subscriber fails or is newly added to
the net.
Also branches from the line-shaped bus and as such the establishment of hi-
erarchic net structures are possible via router nodes.
Repeaters can be used to increase the maximum possible number of nodes
to 110 and to enlarge the network spatial extension (bus length). Although
the network spatial extension depends on the transmission rate, CAN can
also be used for spatially extended networks. The data rates achievable are
of the same order as with other bus systems. However, the maximum possi-
ble cable length is reduced per repeater by 20 - 30 m due to the signal de-
lay.
