Controller Area Network (CAN) Interfaces

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NI-CAN Features in

Measurement & Automation Explorer

Test Panel

You can communicate with a specific CAN channel without

programming using Test Panel, a simple debugging tool to experiment

with CAN channels. Using a graphical interface, the tool reads CAN

data in engineering units and plots or writes to the device.

Bus Monitor

To quickly monitor all CAN bus traffic, use the Bus Monitor, a utility

that provides an easy-to-use interface to view all CAN traffic and log

it to disk. It also provides options to control, display, and view

bus statistics.

NI Spy

NI Spy gives you an easy way to monitor the NI-CAN API calls your

application makes without having to recompile or rebuild. Use it to

verify that your application is working properly, troubleshoot

problems with your application, or verify the communication with

your CAN device. NI Spy dynamically captures and displays all

NI-CAN API calls made by any applications running in the system.

Physical Layer

The CAN physical layer connects the CAN controller to the physical

bus wires. The boards contain the PCI and PXI physical layers. They are

powered internally (from the boards) via a DC-DC converter,

and optically isolated up to 500 V. This isolation protects your

NI-CAN hardware and the PC it is installed in from being damaged by

high-voltage spikes on the CAN bus.

For PCMCIA-CAN cards, the physical layer is implemented inside

the cable. The cables can be powered either internally (from the host

computer) via an onboard DC-DC converter, or externally (from the

CAN bus) via a voltage regulator. PCMCIA-CAN physical layer cables

are included with PCMCIA interfaces.

Connector

PCI-CAN and PXI-846x interfaces have a 9-pin male D-Sub (DB9)

connector for each port. The 9-pin D-Sub connector follows the pinout

recommended by CiA DS 102. Figure 2 shows the 9-pin D-Sub

connector pinout for high-speed and low-speed/fault-tolerant

interfaces. PCMCIA-CAN cables have both a 9-pin male D-Sub and

Note: See the NI CAN hardware and software reference manual for pinouts for single-wire

and software-selectable interfaces.

CAN Device Simulator

The National Instruments CAN Device Simulator, when

communicating with NI CAN and data acquisition (DAQ) hardware

on a PC, provides a tool to demonstrate the concepts of CAN

communication, DAQ, and CAN/DAQ synchronization.

The NI CAN Device Simulator has a function generator, one high-

speed CAN interface, one high-speed CAN monitor connector, a

68-pin DAQ connector, access to the DAQ interface TRIG1, TRIG2,

and FREQOUT pins, and digital input switches.

Figure 1. NI CAN Device Simulator