National Instruments NI 9861 User manual

OPERATING INSTRUCTIONS

NI 9861

1-Port, Low-Speed/Fault Tolerant CAN Module

NI 9861 Operating Instructions 2 ni.com

These operating instructions describe how to use the National

Instruments (NI) 9861 module. For information about installing,

configuring, and programming your system, refer to your system

documentation. The NI 9861 module 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 9861. 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

Caution Do not operate the NI 9861 in a manner not

specified in the user manual or 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.

Hot Surface This icon denotes that the component may be

hot. Touching this component may result in bodily injury.

Safety Guidelines for Hazardous Locations

The NI 9861 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 9861 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.

NI 9861 Operating Instructions 4 ni.com

Caution For Zone 2 applications, install a protection

device between the CAN signals and the NI 9861 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 No. 07 ATEX 0626664X. Each module

is marked II 3G and is suitable for use in Zone 2 hazardous

locations.

Wiring the NI 9861

The NI 9861 has one 9-pin male D-Sub connector that provides

connections to a CAN bus. The NI 9861 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

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 9861.

The NI 9861 requires an external power supply of +9 to +30 V to

operate. Supply power to the NI 9861 VSUP pin from the CAN bus.

Note Power on VSUP is required for CAN operation.

NI 9861 Operating Instructions 6 ni.com

The NI 9861 pinout is listed in Table 1.

Table 1. Pin Assignments for the NI 9861

Connector Pin Signal

1No Connection (NC)

2CAN_L

3COM

4NC

5SHLD

6COM

7CAN_H

8NC

9 VSUP

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. Every device on a low-speed/fault tolerant CAN

network requires a termination resistor for each CAN data line:

RRTH for CAN_H and RRTL for CAN_L.

Figure 1 shows a simplified diagram of a CAN bus with multiple

CAN nodes and proper termination resistor (Rt) locations.

Figure 1. CAN Bus Topology and Termination Resistor Locations

RTL CAN_L RTH CAN_H RTL CAN_L RTH CAN_H RTL CAN_L RTH CAN_H

CAN_H

CAN_L

Low-Speed/Fault-Tolerant

CAN Device

Low-Speed/Fault-Tolerant

CAN Device

Low-Speed/Fault-Tolerant

CAN Device

RtRtRtRtRtRt

NI 9861 Operating Instructions 8 ni.com

Connecting a CAN Bus to the NI 9861

You can connect the NI 9861 to any location on a CAN bus.

Figure 2 shows one example of connecting the NI 9861 directly to

one CAN node.

Figure 2. Connecting the NI 9861 to a CAN Device

Cabling Requirements for the NI 9861

This section deals with cabling specifications, termination

resistors, cable lengths, and the number of CAN nodes that can

exist in a system.

NI 9861

CAN Device

CAN

Cable

(With

Optional

Shield)

(SHLD)

CAN_H

CAN_L

Vsup

COM

(SHLD)

CAN_H

CAN_L

Vsup

COM

Cable Specifications

Cables should meet the physical medium requirements specified in

ISO 11898, shown in Table 2. Belden cable (3084A) meets all

these requirements and should be suitable for most applications.

Termination Resistors

Unlike High-Speed CAN, Low-Speed/Fault Tolerant CAN

requires termination at the Low-Speed/Fault Tolerant CAN

transceiver instead of on the cable itself. Termination requires

two resistors, RTH for CAN_H and RTL for CAN_L. This

configuration allows the NXP Fault-Tolerant CAN transceiver to

detect and recover from bus faults. It is important to determine the

existing network’s overall termination, or the individual device’s

termination, before connecting it to a Low-Speed/Fault Tolerant

Table 2. Specifications for Characteristics of a CAN_H

and CAN_L Pair of Wires

Characteristic Value

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

NI 9861 Operating Instructions 10 ni.com

port. NXP recommends an overall RTH and RTL termination of

100 to 500 Ω(each) for a properly terminated low-speed network.

Termination on the low-speed/fault-tolerant port of the NI 9861 is

set through the NI-XNET software to either 1 kΩor 5 kΩ.

Cable Lengths

ISO 11898-3 (Low-Speed/Fault Tolerant) defines data rates up to

125 kbits/s with the maximum bus length depending on the data

rate used and the busload. To provide a maximum communication

speed of 125 kbits/s, the overall network length should not exceed

40 m. However, you can increase the overall network length by

reducing the actual communication speed. Detailed cable length

recommendations are in the ISO 11898-3 specifications.

Number of CAN Nodes

The maximum number of nodes depends on the electrical

characteristics of the nodes on the network. If all of the nodes

meet the requirements of Low-Speed/Fault-Tolerant CAN, up to

32 nodes may be connected to the bus.

Table of contents

Other National Instruments Control Unit manuals

National Instruments

National Instruments NI 9235 User manual

National Instruments

National Instruments 9225 Manual

National Instruments

National Instruments NI FlexRIO User manual

National Instruments

National Instruments PXI-2503 User manual

National Instruments

National Instruments PXI Terminal Block NI TB-2708 User manual

National Instruments

National Instruments cRIO-9068 User manual

National Instruments

National Instruments NI-9208 Manual

National Instruments

National Instruments NI 5772R User manual

National Instruments

National Instruments NI 9269 User manual

National Instruments

National Instruments NI-9232 User manual

National Instruments

National Instruments Module SCXI-1503 Manual

National Instruments

National Instruments FD-11634 User manual

National Instruments

National Instruments sbRIO-9205 User manual

National Instruments

National Instruments NI 9476E User manual

National Instruments

National Instruments FP-AI-102 User manual

National Instruments

National Instruments NI 9227E User manual

National Instruments

National Instruments SCC-DO01 User manual

National Instruments

National Instruments NI 9218 User manual

National Instruments

National Instruments NI 9758 User manual

National Instruments

National Instruments NI 9475 User manual

National Instruments

National Instruments 9220 Manual

National Instruments

National Instruments VXI-AO-48XDC User manual

National Instruments

National Instruments NI 4472 User manual

National Instruments

National Instruments C Series User manual

Popular Control Unit manuals by other brands

Festo

Festo Compact Performance CP-FB6-E Brief description

Elo TouchSystems

Elo TouchSystems DMS-SA19P-EXTME Quick installation guide

JS Automation

JS Automation MPC3034A user manual

JAUDT

JAUDT SW GII 6406 Series Translation of the original operating instructions

Spektrum

Spektrum Air Module System manual

BOC Edwards

BOC Edwards Q Series instruction manual

KHADAS

KHADAS BT Magic quick start

Etherma

Etherma eNEXHO-IL Assembly and operating instructions

PMFoundations

PMFoundations Attenuverter Assembly guide

GEA

GEA VARIVENT Operating instruction

Walther Systemtechnik

Walther Systemtechnik VMS-05 Assembly instructions

Altronix

Altronix LINQ8PD Installation and programming manual

Eaton

Eaton Powerware Series user guide

WAGO

WAGO 750-407/040-000 manual

Sony

Sony CCU-590 Operation manual

Graco

Graco 25D614 instructions

Task Force Tips

Task Force Tips YE-RF-900 Instructions for installation, safe operation and maintenance

Shini

Shini SPV-U Series manual