Appendix C Cabling Requirements for PXI-8460 Low-Speed CAN
PXI-8461 or PXI-8460 and NI-CAN for Windows NT C-4 www.natinst.com
Cable Specifications
Cables should meet the physical medium requirements specified in
ISO 115 19-2, shown in TableC-2.
Belden cable (3084A) meets all of those requirements, and should be
suitable for most applications.
Number of Devices
The maximum number of devices depends on the electrical characteristics
of the devices on the network. If all of the devices meet the requirements
ofISO 11519-2, at least 20 devices may be connected to the bus. Higher
numbers of devices may be connected if the electrical characteristics of
the devices do not degrade signal quality below ISO 11519-2 signal level
specifications.
Table C-2. ISO 11519-2 Specifications for Characteristics of a CAN_H and
CAN_LPair of Wires
Characteristic Valu e
Length-related resistance 90 mΩ/m nominal
Length-related capacitance:
CAN_L and ground, CAN_H and
ground, CAN_L and CAN_H
30 pF/m nominal