Rockwell Automation 20-750-CNETC PowerFlex Coaxial ControlNet Option Module User Manual

Page 83

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Rockwell Automation Publication 750COM-UM003B-EN-P - November 2012

83

Using Explicit Messaging

Chapter 6

ControlLogix Controller 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 32-bit REAL (floating
point) parameters in a PowerFlex 750-Series drive:

See

DPI Parameter Object on page 115

(Class code 0x93) or

Host DPI

Parameter Object on page 129

(Class code 0x9F) for parameter numbering.

Table 8 - Example Controller Tags to Write Multiple Parameters

Figure 27 - Example Ladder Logic to Write Multiple Parameters

PowerFlex 750-Series Drive Parameter

Write Value

536 - [Accel Time 2]

11.1 Sec

538 - [Decel Time 2]

22.2 Sec

575 - [Preset Speed 5]

33.3 Hz

576 - [Preset Speed 6]

44.4 Hz

577 - [Preset Speed 7]

55.5 Hz

Operand

Controller Tags for Scattered Write Message

Data Type

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

page 79

). 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.

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