User`s guide

Chapter 7: Adept DeviceNet
Table 7-2. Features of a DeviceNet Network
Network Size A maximum of 64 nodes [0 - 63]
Network Length Selectable, end-to-end network distance varies with speed
Data Packets 0-8 bytes
Bus Topology Linear (trunk line/drop line); power and signal on the same network
cable
Bus Addressing Multi-Master and Master/Slave special case; polled
The baud rate of the system depends on the length of the network (end-to-end) and the type of
cable. The following table shows how cable selection and trunk line length affect the max-
imum data rate on the network. The figure DeviceNet Thick Cable on page 87 shows a thick
cable, and the figure DeviceNet Thin Cable on page 88 shows a thin cable.
Table 7-3. DeviceNet Data Rates Relative to Cable Type and Length
Data Rates 125 Kbps 250 Kbps 500 Kbps
Thick Trunk Length 500 m
(1,640 ft)
250 m
(820 ft)
100 m
(328 ft)
Thin Trunk Length 100 m
(328 ft)
100 m
(328 ft)
100 m
(328 ft)
Maximum Drop Length 6 m
(20 ft)
6 m
(20 ft)
6 m
(20 ft)
Cumulative Drop Length 156 m
(512 ft)
78 m
(256 ft)
39 m
(128 ft)
Figure 7-2. DeviceNet Thick Cable
Adept SmartController EX User’s Guide, Rev. D
Page 87 of 94