Chapter 1
Introduction
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National Instruments Corporation
1-11
responds to this remote transmission request by transmitting the button
state in its CAN data frame.
The LED device expects to obtain the state of the LED from a CAN data
frame with standard arbitration ID 5. It expects the frame data to consist of
a single byte—zero to turn the light off, one to turn the light on.
Figure 1-4 shows how NI-CAN objects encapsulate access to this CAN
device network. The ovals in Figure 1-4 indicate NI-CAN objects, and the
dotted lines indicate what each object encapsulates.
Figure 1-4.
Applying NI-CAN Objects to the Example in Figure 1-3
The CAN Network Interface Object encapsulates the entire CAN network
interface. Its attributes are used to configure settings that apply to the
network interface as a whole. For example, the CAN Network Interface
Object contains an attribute you can use to set the baud rate that the network
interface hardware uses for communication. You can also use the CAN
Network Interface Object to communicate on the CAN device network. For
Network
Interface
User
Application
LED
Device
Pushbutton
Device
Arbitration ID 5
Data Frame
Arbitration ID 13
Data Frame
Arbitration ID 13
Remote Frame
CAN Network
Interface Object
CAN Object
for Arbitration
ID 5
CAN Object
for Arbitration
ID 13
