The CAN bus stand for performing experiments was created using original components
from the VW Golf 5. The realistic representation of the components and their connections
is worthy of special mention with this design. In contrast to comparable systems,
no bunch plugs or standardised plug connections are used for the connections between
the original components here. Instead, only original connections from the actual
vehicle are used. This allows the use of original manufacturer documentation and
circuit diagrams, supplied by Volkswagen AG, while also allowing measurements, fault
simulations and diagnostics to be performed in real-world conditions. The function
wall‘s CAN function box serves as the central interface and also provides
additional connection options for accessories.
To facilitate this, the function box includes 10 parallel interfaces for the diagnostic
cable, LIN-Bus and all other CAN bus connections, as well as connections for the
accompanying power supply and earth connection. The supply of the individual components
can be monitored on two LEDs. To prevent short-circuit damage, the parallel connections
are also safeguarded with two fuses. As well as the diagnostic cable, individual
7-pin sub-D sockets are provided for the CAN and LIN-buses to not only allow the
signals to be visualised as voltages on the CAN bus, but also to be able to export
the contents of the CAN messages using the accompanying control unit addresses (identifiers).
When used with a CAN or LIN interface, these allow the messages to be queried/exported
in plain text. The connection to diagnostic test equipment is established using
the 16-pin OBD connector as per the VAG standard. A voltagestabilised 12 V switched
mode power supply with sufficient power output (min. 200 W) is recommended for supplying
voltage to the function wall. Alternatively, a 12 V car battery with sufficient
capacity can be used (12 V 60 AH).