Controller Area Network (CAN) Interfaces

NI CAN Series 2 Interfaces for PCI, PXI, and PCMCIA

• Hardware timing and synchronization

with NI data acquisition, vision,

and motion devices

• 100% bus load; for up to 1 Mb/s

• ISO 11898-compliant for standard

(11-bit) and extended (29-bit)

arbitration IDs

• Philips SJA1000 CAN controller

• Available in high-speed,

low-speed/fault-tolerant,

and single-wire versions

• Hardware timestamping

• Intel 80386EX microprocessor

for timed CAN frame transfer

• Optical isolation up to 500 V

• Import Vector database files

with NI-CAN

Operating Systems

• Windows 2000/NT/XP/Me/98

• LabVIEW Real-Time

Recommended Software

• LabVIEW

• LabWindows/CVI

Other Compatible Software

• C/C++

• Visual Basic 6

Application Software (included)

• Bus monitor utility

Driver Software (included)

• NI-CAN

Overview

CAN interfaces meet the physical and electrical requirements for in-

vehicle automotive networks based on CAN. All CAN interfaces

include NI-CAN device driver software, with which you can import

CAN channels from Vector database files or create them in an

easy-to-use utility and program using a high-level API. With a

National Instruments CAN interface and NI-CAN software, you can use

a desktop, industrial, or notebook PC running Windows for a variety

of CAN applications, including automotive testing and diagnostics,

prototype design, factory automation, and machine control.

CAN Bus and Analog Data Synchronization

Recent advances in automotive test applications demand tighter

integration of CAN and other measurement devices. In many

applications, you need to synchronize the physical parameters

measured in time to correlate the data. You can program this

synchronization in software, but OS latency sometimes introduces

unacceptable delays for certain automotive test applications.

National Instruments CAN, data acquisition, vision, and motion

boards for PCI are equipped to share timing and triggering signals.

In a system, a CAN board can share timing and triggering signals

with data acquisition, image acquisition, or motion control boards,

basing their actions on these signals. Determinism is maintained

between the trigger signal and the desired response because timing

and triggering signals are handled in hardware. The host PC software

interacts only to retrieve the data once it is acquired or to write

new data.

Synchronization is available for PXI, PCI, and PCMCIA-CAN

devices. For PXI modules, the timing signals are shared in the PXI

trigger bus on the backplane; therefore, you do not need additional

cables to take advantage of synchronization. For PCI boards, you can

use a RTSI bus cable to share the signals. For PCMCIA-CAN, a

synchronization cable connects external timing and triggering signals

to the card to achieve synchronization between PCMCIA-CAN and

PCMCIA, USB, or PCI data acquisition hardware.

LabVIEW Real-Time Compatibility

PCI and PXI CAN hardware works with LabVIEW Real-Time running

on a PC or a PXI controller for deterministic control. You can download

your existing NI LabVIEW application to the target without specialized

real-time OS programming knowledge. The real-time performance and

synchronization mean you can use a standard PC or PXI chassis for

applications such as rapid control prototyping, hardware-in-the-loop

testing, and data logging.

Common Hardware

All National Instruments Series 2 CAN devices use the Intel 80386EX

microprocessor to handle communications directly on the interface

device. The 80386EX provides a dedicated environment for reliable,

high-performance CAN communications protocol stack execution.

Because acquisition and transmission timing occur on the board,

CAN frames are not lost due to OS activity such as hard drive

access, mouse movements, or virus scans. The physical layer of all

National Instruments CAN devices fully conforms to the ISO 11898

physical layer specification for CAN and is optically isolated to 500 V.

You can interface to the CAN bus using a 9-pin male D-Sub (DB9)

connector. The Philips SJA1000 CAN controller implements typical

ISO 11898 CAN functionality and offers additional functionality to aid

in system development, such as listen-only mode, sleep/wakeup mode,

error counter access, and self-reception (echo) mode.