National Instruments NI 9882 Operating Instructions Manual

OPERATING INSTRUCTIONS

NI 9882

1-Port DeviceNet Module

These operating instructions describe how to use the National
Instruments (NI) 9882 module. For information about installing,
configuring, and programming your system, refer to your system
documentation. The NI 9882 module requires the latest
NI-DeviceNet software to be installed. The latest version of the
NI-DeviceNet software is available at

Note The safety guidelines and specifications in this

ni.com/downloads.

document are specific to the NI 9882. 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 9882 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 9882 Operating Instructions 2 ni.com

Safety Guidelines for Hazardous Locations

The NI 9882 is suitable for use in Class I, Division 2, Groups A, B,
C, D, T4 hazardous locations; Class I, Zone 2, AEx nA II T4 and
Ex nA II T4 hazardous locations; and nonhazardous locations only.
Follow these guidelines if you are installing the NI 9882 in a
potentially explosive environment. Not following these guidelines
may result in serious injury or death.

Caution Do not disconnect I/O-side wires or connectors

unless power has been switched off or the area is known
to be nonhazardous.

Caution Do not remove modules 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 Zone 2 applications, install the

CompactRIO system in an enclosure rated to at least
IP 54 as defined by IEC 60529 and EN 60529.

© National Instruments Corp. 3 NI 9882 Operating Instructions

Caution For Zone 2 applications, install a protection

device between the CAN signals and the NI 9882 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 II T4 equipment
under DEMKO Certificate No. 07 ATEX 0626664X. Each module
is marked II 3G and is suitable for use in Zone 2 hazardous
locations.

Wiring the NI 9882

The NI 9882 has one 9-pin male D-Sub connector that provides
connections to a CAN bus. The NI 9882 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 module’s isolated reference and serve as the
reference ground for CAN_H and CAN_L. You can connect the
CAN bus reference ground (sometimes referred to as CAN_V–) to

NI 9882 Operating Instructions 4 ni.com

one or both COM pins. The port also has an optional shield pin,
SHLD, that you can connect to a shielded CAN cable. Connecting
SHLD may improve signal integrity and EMC performance in a
noisy environment.

Caution You must use a UL listed ITE power supply

marked LPS with the NI 9882.

The NI 9882 requires an external power supply in the range of
+9 to +30 V to operate. Supply power to the NI 9882 V

Note Power on V

is required for DeviceNET

SUP

SUP

pin.

operation.

The NI 9882 pinout is listed in Table 1.

The NI 9882 features software-selectable bus termination for
High-Speed CAN transceivers. On the NI 9882, you can enable
120

 termination resistors between CAN_H and CAN_L through

an API call. Table 3 lists recommended termination resistor values.

© National Instruments Corp. 5 NI 9882 Operating Instructions

6
7
8
9

1
2
3
4
5

Table 1. Pin Assignments for the NI 9882

Connector Pin Signal

1 No Connection (NC)

2 CAN_L

3 COM

4 NC

5 SHLD

6 COM

7 CAN_H

8 NC

9 V

NI 9882 Operating Instructions 6 ni.com

SUP

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.

Figure 1 shows a simplified diagram of a CAN bus with multiple
CAN nodes and proper termination resistor (R

© National Instruments Corp. 7 NI 9882 Operating Instructions

) locations.

t

CAN

Node

CAN

Node

CAN

Node

R

t

R

t

CAN

Node

CAN_H

CAN_L

CAN_H

CAN_L

CAN_H

CAN_L

CAN_H

CAN_L

Bus Cable Length

Stub

Length

NI 9882 Operating Instructions 8 ni.com

Figure 1. CAN Bus Topology and Termination Resistor Locations