6 - application examples for pico, Chapter 6, Application examples for pico – Rockwell Automation 1760-DNET Pico DeviceNet Communications Module User Manual User Manual

Page 45: Chapter

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Publication 1760-UM003A-EN-P - September 2005

Chapter

6

Application Examples for Pico

Control commands can be used to initiate data exchange for special
services:

Read/Write Date and Time (page 6-2)
Read/Write Image Data (page 6-4)
Read/write function block data (page 6-20).

The DeviceNet master in this case returns to the message transfer
protocol of the explicit messages. All parameters are addressed via the
Service Code 32

hex

. The assigned attribute ID is here used to

distinguish between different parameters.

A data exchange procedure is required in order to ensure the safe
exchange of data via DeviceNet from master to slave and vice versa.

Service Code

Object Address

Class ID

Instance ID

32

Hex

64

Hex

01

Hex

TIP

The I/O data retain their previously defined state
while a control command is being executed. The I/O
data will not be updated until data exchange for the
control command has been terminated.

IMPORTANT

You may use only the values specified for the
instruction code.

Verify data to be transferred in order to avoid
unnecessary errors.

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