I-8124W DeviceNet Master API functions User’s Manual (V 1.6) 2021/10/04
22
2.4 Wire connection
In order to minimize the reflection effects on the CAN bus line, the CAN
bus line has to be terminated at both ends by two terminal resistances as in
the following figure. According to the ISO 11898-2 spec, each terminal
resistance is 120Ω (or between 108Ω~132Ω). The length related resistance
should have 70 mΩ/m. Users should check the resistances of the CAN bus,
before they install a new CAN network.
12
0
Ω
12
0
Ω
CAN_H
CAN_L
Device N
Device 2
Device 1
. . .
Figure 2.4 CAN bus network topology
Figure 2.5 CAN bus wire connection without DC power
Figure 2.6 CAN bus wire connection with 24VDC power
