Western Reserve Controls WRC-CANR-DF-DN, User Manual

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Western Reserve Controls WRC-CANR-DF-DN and –SM User’s Manual
PUB 14.2 Revision 4.03
10
Table 4-6 Network Maximum Lengths - DeviceNet
Baud Rate
Trunk Line Length Drop Length
Maximum Distance Maximum Cumulative
Meters Feet Meters Feet Meters Feet
125 Kbits/s 500 m 1640 ft 6 m 20 ft 156 m 512 ft.
250 Kbits/s 250 m 820 ft 6 m 20 ft 78 m 256 ft.
500 Kbits/s 100 m 328 ft 6 m 20 ft 39 m 128 ft.
DeviceNet has a limit of 64 nodes per network for any baud rate.
Table 4-7 Network Maximum Lengths - SDS
Baud Rate
Trunk Line Length
(maximum)
Drop Length
(maximum)
No. of
Nodes
Meters Feet Meters Feet
125 Kbits/s 457.2 1500 3.6 12 64
250 Kbits/s 182.8 600 1.8 6 64
500 Kbits/s 91.4 300 0.9 3 64
1 Mbits/s 22.8 75 0.3 1 32
SDS has a limit of 32 nodes per network for any baud rate.
Note: The CANR-DF CAN bus extender does not enable the user to add more nodes. In addition,
it is transparent to the network and does not count as an addressed device.
4.5.2. Network Termination
A CAN-Bus system must be terminated at each end of a copper trunk line . The host
controller and the last node device or WRC CAN-Bus Extender on the network must always be terminated
to match impedance and eliminate reflections, even if only two nodes are present. Follow the information
below when using a CANR-DF.
The CANR Series IV has a built-in terminator, which can be selectively included or omitted from
the network. To include the on-board terminator (on the DeviceNet side), install jumper W1; or remove the
W1 jumper if the on-board terminator in not desired. The CANR is shipped from the factory with the
jumper installed. See Figure 4-1 for the location of the jumper.
Trunk line use:
For the purpose of network termination, the CANR-DF is treated as the last node on the copper
section of the trunk network (side A) to which it is connected. Therefore, when a CANR-DF is used directly
in a trunk line, it must be terminated on side A. The terminating resistor built into the CANR-DF at W1
must be installed, or another terminator at the end of the line could be used in the place of the W1
terminator.
Drop line use: