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Formatting a message to write a single parameter – Rockwell Automation 25-COMM-E2P PowerFlex 25-COMM-E2P Dual-Port EtherNet/IP Adapter User Manual

Page 77

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Rockwell Automation Publication 520COM-UM003A-EN-E - June 2013

77

Using Explicit Messaging

Chapter 6

Formatting a Message to Write a Single Parameter

Set Attribute Single Message Configuration Screens

The following table identifies the data that is required in each box to configure a
CompactLogix controller message to write a single parameter.

Configuration Tab

Example Value

Description

Message Type
Service Type

(1)

Service Code

(1)

Class
Instance

(2)

Attribute

(3)

Source Element
Source Length
Destination

(1) The default setting for Service Type is “Custom,” enabling entry of a Service Code not available from the Service Type pull-down

menu. When choosing a Service Type other than “Custom” from the pull-down menu, an appropriate Hex. value is automatically
assigned to the Service Code box which is dimmed (unavailable).

(2) The instance is the parameter number in the drive.
(3) Setting the Attribute value to “9” will write the parameter value to the drive’s Non-Volatile Storage (EEPROM) memory, so the

parameter value will remain even after the drive is power cycled. Important: When set to “9,” be very cautious as the EEPROM may
quickly exceed its life cycle and cause the drive to malfunction. Important: If you need to make frequent parameter changes using
Explicit Messages, set parameter C121 [Comm Write Mode] to 1 “RAM only”.

CIP Generic
Get Attribute Single
10 (Hex.)
93

(5)

41 (Dec.)
9
Accel_Time_1

(6)

2 bytes

(5) See

Explicit Messaging Class Code Compatibility with PowerFlex 520-series Drives on page 74

for limitations of PowerFlex 520-series

drives when using DPI Parameter Object Class code 0x93 for explicit messaging.

(6) In this example, Accel Time 1 is a 16-bit parameter requiring the Data Type field to be set to “INT” when creating the controller tag.

Also, the Source Length field on the Message Configuration screen must correspond to the selected Data Type in bytes (for example,
2 bytes for an INT). See the drive documentation to determine the size of the parameter and its data type.

Used to access the DPI Parameter Object in the adapter.
This service is used to read a parameter value.
Code for the requested service.
Class ID for the DPI Parameter Object.
Instance number is the same as parameter number.
Attribute number for the Parameter Value attribute.
Name of the tag for any service data to be sent from the scanner
or bridge to the drive.
Number of bytes of service data to be sent in the message.
Leave blank (not applicable).

Communication Tab Example Value

Description

Path

(4)

(4) Click Browse to find the path, or type in the name of the device listed in the I/O Configuration folder (for this example,

PowerFlex_52X_Drive).

PowerFlex_52X_Drive

The path is the route that the message will follow.

Tag Tab

Example Value

Description

Name

Single_Write_Message

The name for the message.