General Information on CAN Bus Wiring
The wiring of the CAN bus requires three conductors (CAN Hi, CAN Lo and CAN Com). The conductors for CAN Hi and CAN Lo must be twisted wires. At a bit rate of 250 kbit/s, the bus may only have a maximum wire length of 250 m (820') and must be terminated at both ends by a terminating resistor of 120 Ω between the CAN Hi and CAN Lo conductors to prevent reflections.
The diagram shows an example of the wiring for four devices:
|
First device |
Second-to-last device |
|||
|
Second device |
Last device |
CAN Bus Wiring Note the following when connecting the CAN bus:
|
The TempScan20 is delivered with a bit rate set to 250 kbit/s.
Shielding and Grounding
Use a shielded CAN bus cable. The CAN bus shield is usually grounded via the PowerView3. Further information on this can be found in the PowerView3 operating manual.
Settings on the Devices
All connected devices are designated as nodes on the CAN bus. Each node is identified by a CANopen®‑node ID. These node numbers must be indicated both in the connected devices as well as in the configuration of the PowerView3. Refer to the operating manuals of the respective devices for instructions on how to set the node ID for each device and to determine if further settings must be made to communicate via the CAN bus.
A node ID can only be assigned once within a CAN bus and must be a number between 1 and 127. Note that some devices use several node numbers. The node numbers must be assigned in the configuration after start-up of the PowerView3.
Overview of the CAN bus Setting up the CAN field bus requires the following settings:
|
CANopen® protocol If you require information on the CANopen® protocol, contact your MOTORTECH contact person. |