User Manual

EtherNet/IP Communications Support DI[D-SE-0030784.1.6]
80 EIO0000001601 Draft 2013/07/17
Read Applicat ion Example
Read Application Example
Introduction
This example describes the implementation of the Modbus object (see page 67) for reading 123
words using the DATA_EXCH function. Refer to the Unity Pro online help for more information
about explicit message.
Example
CIP Request Description
The DataToSend variable identifies the type of explicit message and the CIP request:
Variable Description Value (hex)
DataToSend[0] CIP request service information:
” High byte = request size in words: 16#02 (2 decimal)
” Low byte = service code: 16#4E (78 decimal)
16#024E
DataToSend[1] CIP request class information:
” High byte = class: 16#44 (68 decimal)
” Low byte = class segment: 16#20 (32 decimal)
16#4420
DataToSend[2] CIP request instance information:
” High byte = instance: 16#01 (1 decimal)
” Low byte = instance segment: 16#24 (36 decimal)
16#0124