ABB FCAN-01, User Manual

Page: 34 / 176

34 Electrical installation
AC and DC parameters for the CANopen network

Bus cable and termination resistors
The cables, connectors, and termination resistors used in
CANopen networks must meet the requirements specified in ISO
11898.
The table below lists the standard values for DC parameters for
CANopen networks with less than 64 nodes:
With drop cables the recommended cable cross-section is
0.25…0.34 mm
2
.
In addition to the cable resistance, the real resistance of the
connectors should be taken into account in voltage drop
calculation. The transmission resistance of one connector should
be 2.5...10 mohm.
The following table lists the maximum bus cable length for different
node numbers (n), when
•
minimum dominant value V
diff.out.min
= 1.5 V
•
minimum differential input resistance R
diff.min
= 20 kohm
•
requested differential input voltage V
th.max
= 1.0 V
•
minimum termination resistance R
T.min
= 118 ohm.
Bus length
[m]
Bus cable
1)
Termination
resistance
[ohm]
Baud rate
[kbit/s]
Length-
related
resistance
[mohm/m]
Cross-
section
[mm
2
]
0…40 70 0.25…0.34 124 1000 at 40 m
40…300 < 60 0.34…0.6 150…300 > 500 at 100 m
300…600 < 40 0.5…0.6 150…300 > 100 at 500 m
600…1000 < 26 0.75…0.8 150…300 > 50 at 1 km
1)
Recommended cable for AC parameters: 120 ohm impedance and 5 ns/m line delay