User`s guide

DeviceNet Physical Layer and Media
Adept SmartController User’s Guide, Rev. K 93
Termination of the DeviceNet Network
The DeviceNet network uses the Controller Area Network (CAN) bus as the physical
layer. This requires that the trunk line of your DeviceNet network be terminated with a
resistor at each end. This terminates the signal lines.
The terminating resistor:
• Prevents reflection of communication signals on the network.
• Connects the two signal conductors.
• Must be sealed if the end node uses a sealed tee.
• Must be open if the end node uses an open-style tap.
When using the open-style terminating resistor, connect a 121 ohm,
¼ W resistor to
CAN_H and CAN_L (between blue and white data-pair wires).
NOTE: A terminating resistor must also be used whenever a short drop
line exceeds 6 m (20 ft.).
Figure B-5. Example of a Terminating Resistor Installation on a DeviceNet Bus
Table B-4. DeviceNet Connector Styles
Connector Description
Open plugable Uses screws to attach cable wires to a removable
connector
Open hard-wire Uses wires attached directly to screw terminals
Sealed mini-style Attaches to taps and thick or thin cable
Sealed micro-style Attaches to thin cable only – has a reduced
current rating
Pin 4 Pin 5
Terminating
Resistor