Rockwell Automation 1500 DeviceNet MV Controllers Installation Instructions - Manual (Page 7)

Chapter
2
1500-IN057C-EN-P – June 2013
Designing Cable Systems
When designing DeviceNet systems, it is necessary to consider the
following (refer to publication DNET-UM072_-EN-P for additional
requirements):
 Number of nodes does not exceed 64, with three nodes reserved for
scanner (node 00), PC (node 62), and new device (node 63).
 Total power load and distribution points do not exceed 8A
 Total trunk length does not exceed the maximum allowable per the
network baud rate: 246 feet (75 m) at 500 kbps or 492 feet (150 m)
at  250 kbps.
 Cumulative drop length does not exceed the maximum allowable
per the network baud rate: 128 feet (39 m) at 500 kbps or 256 feet
(78 m) at 250 kbps.
 Individual drop lengths do not exceed 20 feet (6 m)
For IntelliCENTER, 500 kbps provides optimum
performance, but 250 kbps may be used. (125
kbps is not possible).
 A separate DeviceNet network is recommended for each low
voltage or medium voltage controller line-up, to simplify network
and medium voltage controller design. This approach generally
allows the network to operate at the maximum speed (500 kbps)
and reduces the likelihood of encountering limits for node count,
power consumption, and cable lengths.
 The DeviceNet should be bridged to ControlNet or Ethernet (using
optional hardware) in the MV controller if the line-up is to be
located beyond the maximum DeviceNet trunk length.
I M P O R T A N T I M P O R T A N T