Cable Selection - ICP DAS USA I-7530A-MR-G User Manual

Cable Selection

2.7
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 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 120
CAN lines. How to decide a cable type, cable length, and terminator
depends on the baud rate in the CAN bus network, please refer to the
following table 2-4.
Figure 2-18: Un-shielded Twisted Pair (UTP)
Bus speed
50k bit/s 0.75~0.8mm2
at 1000m
100k bit/s 0.5~0.6 mm2
at 500m
500k bit/s 0.34~0.6mm2
at 100m 22AWG, 20AWG
1000k bit/s 0.25~0.34mm2
at 40m 23AWG, 22AWG
Note: The AWG means a standard method used to measure wire. The
numbering system works backwards from what people would think, the
thicker (heavier) the wire, the lower the number. For example: a 24AWG
wire is thicker/heavier than a 26AWG wire.
I-7530A-MR Modbus RTU to CAN Converter User's Manual (Version 1.08, 07/2019) ------------- 20
Ω
(Ohm) terminator resistor is connected between the
Table 2-4: Cable selection
Cable type
18AWG
20AWG
Cable
Resistance/m
70 mOhm
< 60 mOhm
< 40 mOhm
< 40 mOhm
Terminator Bus Length
150~300
600~1000m
Ohm
150~300
300~600m
Ohm
127 Ohm 40~300m
124 Ohm 0~40m