108
• DeviceNet
Network Architecture
WAGO-I/O-SYSTEM 750
DeviceNet
5.2.1.3 Maximum Bus Length
In the following table, the permitted cable length is represented in dependence
of the Baud rate. Here, a differentiation is made between the maximum length
for a transmission using a thick and a thin cable.
Bus length
Tap line length
Baud rate
Thick + Thin Cable
only
Thick
Cable
only
Thin
Cable
maximal
cumulated
500 kbit/s
L
Tick
+ L
Thin
≤
100 m (328 ft)
100 m
(328 ft)
100 m
(328 ft)
6 m (19,6 ft)
39 m (127,9 ft)
250 kbit/s
L
Tick
+ 2,5
•
L
Thin
≤
250 m (820,2 ft)
250 m
(820,2 ft)
100 m
(328 ft)
6 m (19,6 ft)
78 m (255,9 ft)
125 kbit/s
L
Tick
+ 5
•
L
Thin
≤
500 m (1640,4 ft)
500 m
(1640,4 ft)
100 m
(328 ft)
6 m (19,6 ft)
156 m (511,8 ft)
Tab. 5-1: Maximum bus length dependent on the set Baud rate
When specifying the maximum cable lengths, it is made sure that communica-
tion is possible between two nodes located at maximum distance to each other
(worst case).
5.2.2 Cabling
The connection of a WAGO fieldbus node to the DeviceNet bus cable is made
by the supplied 5-pole plug (Multi Connector 231).
Fieldbus
connection
Series 231
(MCS)
CAN_High
drain
CAN_Low
V-
V+
Fig. 5-1: Plug assignment for the fieldbus connection
For wiring using a screened cable, the plus is assigned the connections V+, V-
for the voltage supply and with CAN_High, CAN_Low for data transmission.
The 24 V field bus supply is fed by an external fieldbus network power
supply.
CAN_High and CAN_Low are two physically different bus levels.
The cable screen is connected to the drain connection.
This is terminated with a 1 M
Ω
resistor to the DIN rail via the clip on the
bottom of the Coupler/Controller. The DIN rail must then be directly con-
nected to the Grounding Stud that must be connected to Earth Ground. We
strongly recommend a central Earth Ground for the entire DeviceNet Bus con-
ductor screening. A low Ohm connection of the screening on PE terminal can
only be made externally.
