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Rockwell Automation 25B PowerFlex 525 Embedded EtherNet/IP Adapter User Manual

Page 77

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Rockwell Automation Publication 520COM-UM001B-EN-E - March 2013

77

Using Explicit Messaging

Chapter 6

CompactLogix Example Ladder Logic Program to Write Multiple
Parameters

A Scattered Write message is used to write to multiple parameters. This write
message example writes the following values to these five 16-bit parameters in a
PowerFlex 525 drive:

Example Controller Tags to Write Multiple Parameters

Example Ladder Logic to Write Multiple Parameters

PowerFlex 525 Drive Parameters

Write Value

A442 [Accel Time 2]

11.10 Sec

A443 [Decel time 2]

22.20 Sec

A415 [Preset Freq 5]

33.30 Hz

A416 [Preset Freq 6]

44.40 Hz

A417 [Preset Freq 7]

55.50 Hz

Operation

Controller Tags for Scattered Write Message

Data Types

XIC

Execute_Scattered_Write_Message

BOOL

MSG

Scattered_Write_Message

MESSAGE

IMPORTANT

If the explicit message scattered write must be written continuously, then use
a separate explicit message single write for each parameter using DPI
Parameter Object Class code 0x93 and attribute A (see

CompactLogix –

Formatting a Messageto Write a Single Parameter on page 73

). Attribute A

writes to RAM—not NVS (EEPROM) memory. This example scattered write
message using attribute 0 writes to NVS. Over time, continuous writes will
exceed the EEPROM life cycle and cause the drive to malfunction.

If you need to make frequent parameter changes using Explicit Messages, set
parameter C121 [Comm Write Mode] to 1 “RAM only”.

Execute_Scattered_Write_Message

Message
Message Control

Scattered_Write_Message

MSG

EN
DN
ER