Using acyclic messaging, About acyclic messaging, Chapter 6 – Rockwell Automation 25-COMM-P PowerFlex PROFIBUS DPV1 Adapter User Manual
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Rockwell Automation Publication 520COM-UM004A-EN-E - November 2013
47
Chapter
6
Using Acyclic Messaging
This chapter provides information and examples that explain how to use
PROFIBUS Class 1 DPV1 Acyclic Messaging to configure and monitor the
adapter installed and connected to the PowerFlex 520-series drive.
for information about the I/O Image, using Logic
Command/Status, Reference/Feedback, and Datalinks.
About Acyclic Messaging
Acylic messaging is used to transfer data that does not require continuous
updates. Acylic messaging, or DPV1 messaging in the case of the 25-COMM-P
adapter, is also used to configure and monitor drive’s parameters on a
PROFIBUS network.
Host (drive) parameters as well as Device (adapter)
parameters can be accessed using acyclic messaging for a PowerFlex 520-series
drive. For a full list of
Host (drive) parameters, see the PowerFlex 520-Series
Adjustable Frequency AC Drive User Manual, publication
for
a list of
Device (adapter) parameters, see
. To use
acyclic messaging read and write services, you need the values of the slot and
index to which a parameter is associated. Value ranges for slot and index are
shown in
PROFIBUS Slot and Index for Drive and Adapter Parameters on
Topic
Page
Acyclic Messaging for DPV1 Class
ATTENTION: Risk of injury or equipment damage exists. The examples in this
publication are intended solely for purposes of example. There are many
variables and requirements with any application. Rockwell Automation, Inc.
does not assume responsibility or liability (to include intellectual property
liability) for actual use of the examples shown in this publication.
ATTENTION: Risk of equipment damage exists. If Acyclic Messages are
programmed to write parameter data to Non-Volatile Storage (NVS) frequently,
the NVS will quickly exceed its life cycle and cause the drive to malfunction. Do
not create a program that frequently uses Acyclic Messages to write parameter
data to NVS. Datalinks do not write to NVS and should be used for frequently
changed parameters.
ATTENTION: If you need to make frequent parameter changes using Acyclic
Messages, set Host parameter C121 [Comm Write Mode] to 1 “RAM only”.