ICP DAS USA I-7530, Руководство пользователя

Страница: 74 / 101

I-7530, I-7530A, I-7565, I-7530-FT, tM-7530, tM-7530A, tM-7565 User Manual Version 1.6 Page:
74
Copyright © 2018 ICP DAS Co., Ltd. All Rights Reserved E-mail: service@icpdas.com
5.1 Cable selection
The CAN bus is a balanced (differential) 2-wire interface running over either a
Shielded Twisted Pair (STP), Un-shielded Twisted Pair (UTP), or Ribbon cable. The
CAN-L and CAN-H wire start on one end of the total CAN network that a terminator
resistor of 120 Ohm is connected between CAN-L and CAN-H. The cable is connected
from CAN node to CAN node, normally without or with short T connections. On the
other end of the cable again a 120Ω (Ohm) terminator resistor is connected between
the CAN lines.
Figure: Un-shielded Twisted Pair (UTP)
How to decide a cable type, cable length, and terminal resistor depends on the
baud rate in the CAN BUS network, please refer to the following table.
CAN baud rate Cable type
Cable
resistance /
meter
terminator
resistor
Bus Length
50k bit/s
，
1000m
0.75~0.8mm2
18AWG
70 mOhm
150~300
Ohm
600~1000m
100k bit/s
，
500m
0.5~0.6 mm2
20AWG
< 60 mOhm
150~300
Ohm
300~600m
500k bit/s
，
100m
0.34~0.6mm2
22AWG, 20AWG
< 40 mOhm 127 Ohm 40~300m
1000k bit/s
，
40m
0.25~0.34mm2
23AWG, 22AWG
< 40 mOhm 124 Ohm 0~40m