Rockwell Automation DeviceNet Media Design Installation Guide - Manual (Page 23)

Publication DNET-UM072C-EN-P - July 2004
Get Started 1-13
The terminating resistor reduces reflections of the communication signals on
the network. Choose your resistor based on the type of cable (round or flat) and
connector (open or sealed) you use.
For round cable:
– the resistor may be sealed when the end node uses a sealed T-port tap
– the resistor may be open when the end node uses an open-style tap
For flat cable:
– the resistor is a snap-on cap for the KwikLink connector base, available
in sealed and unsealed versions
You must attach a terminating resistor of 121 Ω , 1%, 1/4W or larger, to each end
of the trunk cable. You must connect these resistors directly across the blue and
white wires of the DeviceNet cable.
The following terminating resistors provide connection to taps and the trunk
line.
• sealed-style terminating resistors. Male or female connections attach to:
– trunk line ends
– T-Port taps
ATTENTION
If you do not use terminating resistors as described, the
DeviceNet cable system will not operate properly.
Description Catalog number
Sealed male terminator 1485A-T1M5
Sealed female terminator 1485A-T1N5
Terminate
the Network
TR TR
2
To verify the resistor connection, disconnect
power and measure the resistance across the
Can_H and Can_L lines (blue and white wires,
respectively). This reading should be
approximately 50-60
Ω.
Do not put a terminating resistor on a node with
a non-removable connector. If you do so, you
risk network failure if you remove the node. You
must put the resistor at the end of the trunk line.
Female Side Male Side
sealed male terminator sealed female terminator
mini T-Port tap
41854