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PAVIRO Router
Pin
2
4
5
Table 6.2: Assignment of the CAN BUS interface
Cable specification
In accordance with the ISO 11898-2 standard, shielded twisted-pair cables with an impedance
of 120 ohms must be used as the data transfer cable for the CAN bus. A terminating resistance
of 120 ohms must be provided at both ends as the cable terminator. The maximum bus length
depends on the data transmission rate, the type of data transmission cable, and the number
of bus participants.
Recommended connecting cable: shielded twisted-pair, CAT5, 100 / 120 Ω.
Bus length (in
m)
0 to 40
40 to 300
300 to 600
600 to 1000
Table 6.3: Relationships for CAN networks with up to 64 participants
If there are long cables and several devices on the CAN bus, terminating resistors with ohm
ratings higher than the specified 120 ohms are recommended in order to reduce the resistive
load for the interface drivers, which in turn reduces the voltage loss from one cable end to
another.
The following table allows initial estimates for the required cable cross-section for different
bus lengths and various numbers of bus participants.
Bus length (in m)
100
250
500
Table 6.4: CAN BUS cable cross-section
If a participant cannot be directly connected to the CAN bus, a stub line (branch line) must be
used. Since there must always be precisely two terminating resistors on a CAN bus, a stub line
cannot be terminated. This creates reflections, which impair the rest of the bus system. To
Bosch Security Systems, B.V.
Designation
CAN_GND
CAN_H (+)
CAN_L (-)
Data transmission cable
Resistance per unit
Cable cross-
(in mΩ/m)
section
< 70
0.25 to 0.34 mm²
AWG23, AWG22
< 60
0.34 to 0.6 mm²
AWG22, AWG20
< 40
0.5 to 0.6 mm²
AWG20
< 26
0.75 to 0.8 mm²
AWG18
Number of devices on the CAN Bus
32
0.25 mm² or AWG24
0.34 mm² or AWG22
0.75 mm² or AWG18
User manual
Cable color
T568A
Green
Blue
Blue stripes
Termination (in
Ω)
124
127
150 to 300
150 to 300
64
0.34 mm² or AWG22
0.5 mm² or AWG20
0.75 mm² or AWG18
Connection | en
17
T568B
Orange
Maximum data
transmission
rate
1000 kbit/s at
40 m
500 kbit/s at
100 m
100 kbit/s at
500 m
62.5 kbit/s at
1000 m
100
0.34 mm² or AWG22
0.5 mm² or AWG20
1.0 mm² or AWG17
2022-11 | 07 | F01U306901
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