National Instruments NI-XNET CAN HS/FD User manual

OPERATING INSTRUCTIONS
NI-XNET CAN HS/FD
Transceiver Cable

2|ni.com |NI-XNET CAN HS/FD Transceiver Cable Instructions
These operating instructions describe how to use the NI-XNET
CAN HS/FD Transceiver Cable. For information about installing,
configuring, and programming your system, refer to your system
documentation. The transceiver cable requires the latest NI-XNET
software to be installed. The latest version of the NI-XNET
software is at ni.com/downloads.
Note The safety guidelines and specifications in this
document are specific to the NI-XNET CAN HS/FD
Transceiver Cable. The other components in your system
may not meet the same safety ratings and specifications.
Refer to the documentation for each component in your
system to determine the safety ratings and specifications
for the entire system.
Safety Guidelines
Operate the NI-XNET CAN HS/FD Transceiver Cable only as
described in these operating instructions.
Hot Surface This icon denotes that the component may
be hot. Touching this component may result in bodily
injury.

NI-XNET CAN HS/FD Transceiver Cable Instructions |© National Instruments |3
Caution Do not operate the NI-XNET CAN HS/FD
Transceiver Cable in a manner not specified in these
operating instructions. Product misuse can result in a
hazard. You can compromise the safety protection built
into the product if the product is damaged in any way. If
the product is damaged, return it to National Instruments
for repair.
Safety Guidelines for Hazardous Locations
The NI-XNET CAN HS/FD Transceiver Cable is suitable for use
in Class I, Division 2, Groups A, B, C, D, T4 hazardous locations;
Class I, Zone 2, AEx nA IIC T4 and Ex nA IIC T4 hazardous
locations; and nonhazardous locations only. Follow these
guidelines if you are installing the NI-XNET CAN HS/FD
Transceiver Cable in a potentially explosive environment. Not
following these guidelines may result in serious injury or death.
Caution Do not disconnect bus-side connector unless
power has been switched off or the area is known to be
nonhazardous.

4|ni.com |NI-XNET CAN HS/FD Transceiver Cable Instructions
Caution Do not unplug transceiver cable unless power
has been switched off or the area is known to be
nonhazardous.
Caution Substitution of components may impair
suitability for Class I, Division 2.
Caution For Division 2 and Zone 2 applications, install
the system in an enclosure rated to at least IP 54 as
defined by IEC 60529 and EN 60529.
Caution For Division 2 and Zone 2 applications, install
a protection device between the CAN bus and the
NI-XNET CAN HS/FD Transceiver Cable CAN pins.
The device must prevent the CAN Port-to-COM voltage
from exceeding 55 V if there is a transient overvoltage
condition.
Special Conditions for Safe Use in Europe
This equipment has been evaluated as Ex nA IIC T4 equipment
under DEMKO Certificate 12 ATEX Number (1202658X). Each
transceiver cable is marked II 3G and is suitable for use in
Zone 2 hazardous locations.

NI-XNET CAN HS/FD Transceiver Cable Instructions |© National Instruments |5
Caution You must make sure that transient disturbances
do not exceed 140% of the rated voltage.
Caution The system shall be mounted in an ATEX
certified enclosure with a minimum ingress protection rating
of at least IP54 as defined in IEC/EN 60529 and used in an
environment of not more than Pollution Degree 2.
Caution The enclosure must have a door or cover
accessible only by the use of a tool.
Mounting the NI-XNET CAN HS/FD
Transceiver Cable
Caution The NI-XNET CAN HS/FD Transceiver Cable
is a thermally active device that dissipates heat.
Refer to the user manual of the host this device directly
connects to for specific information regarding thermal
management. Not following mounting requirements may
affect the system ambient temperature and/or the
measurement accuracy of modules in the system.

6|ni.com |NI-XNET CAN HS/FD Transceiver Cable Instructions
The Transceiver Cable is intended to be routed and strain relieved
similar to other cables, and does not require a special mounting
accessory.
Wiring to the NI-XNET CAN HS/FD
Transceiver Cable
The NI-XNET CAN HS/FD Transceiver Cable is used with a
compatible NI-XNET Transceiver Cable host port.
Figure 1. NI-XNET CAN HS/FD Transceiver Cable Connections
The NI-XNET CAN HS/FD Transceiver Cable has one 9-pin male
D-Sub connector that provides connections to a CAN bus. The
NI-XNET CAN HS/FD Transceiver Cable has pins for CAN_H
and CAN_L, to which you connect the CAN bus signals. Connect
these signals using twisted-pair cable.
The port has two common pins (COM) that are internally
connected to the transceiver cable’s isolated reference and serve as
To CAN Bus
To Transceiver
Cable Host
NATIONAL INSTRUMENTS

NI-XNET CAN HS/FD Transceiver Cable Instructions |© National Instruments |7
the reference ground for CAN_H and CAN_L. You can connect the
CAN bus reference ground (sometimes referred to as CAN_V) to
one or both COM pins.
The D-Sub connector shell connects through the NI-XNET CAN
HS/FD Transceiver Cable shielding to the connector on the host
port end. The shielding does not electrically connect to the COM
signals.
The NI-XNET CAN HS/FD Transceiver Cable gets power from
the XNET host port. No external power from the CAN bus is
required.
Note The NI-XNET CAN HS/FD Transceiver Cable is
internally powered, but LIN and some other cables may
require external power when the bus standard requires it.
The NI-XNET CAN HS/FD Transceiver Cable pinout is listed in
Table 1.
The NI-XNET CAN HS/FD Transceiver Cable features
software-selectable bus termination for High-Speed CAN
transceivers. On the NI-XNET CAN HS/FD Transceiver Cable,
you can enable 120 Ωtermination resistors between CAN_H and

8|ni.com |NI-XNET CAN HS/FD Transceiver Cable Instructions
CAN_L through an API call. If you choose to use external
termination, Table 3 lists recommended termination resistor
values.
Table 1. Pin Assignments for the NI-XNET CAN HS/FD
Transceiver Cable
Connector Pin Signal
1No Connection (NC)
2CAN_L
3COM
4NC
5NC
6COM
7CAN_H
8NC
9NC
6
7
8
9
1
2
3
4
5

NI-XNET CAN HS/FD Transceiver Cable Instructions |© National Instruments |9
CAN Bus Topology and Termination
A CAN bus consists of two or more CAN nodes cabled together.
The CAN_H and CAN_L pins of each node are connected to the
main CAN bus cable through a short connection known as a “stub.”
The pair of signal wires, CAN_H and CAN_L, constitutes a
transmission line. If the transmission line is not terminated,
each signal change on the bus causes reflections that may cause
communication errors. Because the CAN bus is bidirectional, both
ends of the cable must be terminated. However, this requirement
does not mean that every node on the bus should have a termination
resistor; only the two nodes at the far end of the cable should have
termination resistors.

10 |ni.com |NI-XNET CAN HS/FD Transceiver Cable Instructions
Figure 2 shows a simplified diagram of a CAN bus with multiple
CAN nodes and proper termination resistor (Rt) locations.
Figure 2. CAN Bus Topology and Termination Resistor Locations
CAN
Node
CAN
Node
CAN
Node
RtRt
CAN
Node
CAN_H
CAN_L
CAN_H
CAN_L
CAN_H CAN_L CAN_H CAN_L
Bus Cable Length
Stub
Length