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SmartController EX User's Guide
11069-000 Rev. H
6.4 DeviceNet Physical Layer and Media
1
2
4
3
Figure 6-4. DeviceNet Connector Styles
Table 6-7. DeviceNet Connector Style Descriptions
Item
Connector Style
Description
1
Unsealed screw con-
nector
Uses screws to attach wires to a removable con-
nector
2
Unsealed hard-wired
Uses wires attached directly to screw terminals
3
Sealed mini-style
Attaches to taps and thick or thin cable
4
Sealed micro-style
Attaches to thin cable only – has a reduced current
rating
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:
l
Prevents reflection of communication signals on the network.
l
Connects the two signal conductors.
l
Must be sealed if the end node uses a sealed tee.
l
Must be open if the end node uses an open-style tap.
The SmartController EX has a terminating resistor built-in, which can be used for one end of
the DeviceNet network.
It is possible to disable this resistor by moving the JP2 jumper, which is internal to the
SmartController EX. If you disable this resistor, a terminating resistor must then be used
whenever a short drop line exceeds 6 m (20 ft). See the following figure.
