Rockwell Automation 20-750-ENETR PowerFlexDual-Port EtherNet/IP Option Module User Manual
Page 102
102
Rockwell Automation Publication 750COM-UM008A-EN-P - July 2012
Chapter 6
Using Explicit Messaging (Adapter mode only)
ControlLogix – Formatting a Message to Read a Single Parameter
Figure 25 - Get Attribute Single Message Configuration Dialog Boxes
The following table identifies the data that is required in each box to configure a
message to read a single parameter.
Configuration Tab
Example Value
Description
Message Type
Service Type
(1)
Class
Instance
(2)
Attribute
Source Element
Source Length
Destination
CIP Generic
Get Attribute Single
e (Hex.)
93 or 9F (Hex.)
(4)
7 (Dec.)
9 (Hex.)
—
0 bytes
Output_Current
(5)
Used to access the DPI Parameter Object in the option module.
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.
Leave blank (not applicable).
Number of bytes of service data to be sent in the message.
The tag where the data that is read is stored.
Communication Tab
Example Value
Description
Path
(3)
My_PowerFlex_755_Drive
The path is the route that the message will follow.
Tag Tab
Example Value
Description
Name
Single_Read_Message
The name for the message.
(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 (Port 0). For example, to read parameter 4 of a peripheral in Port 5 of a PowerFlex 755 drive, the
instance would be 21504 + 4 = 21508. See
DPI Parameter Object on page 163
(Class code 0x93) or
Host DPI Parameter Object on page 177
(Class
code 0x9F) to determine the instance number.
(3) Click Browse to find the path, or type in the name of the device listed in the I/O Configuration folder (for this example,
My_PowerFlex_755_Drive).
(4) See
for limitations of PowerFlex 750-Series drives when using DPI Parameter Object Class code 0x93 or Host DPI Parameter
Object Class code 0x9F for explicit messaging.
(5) In this example, Output Current is a 32-bit REAL (floating point) parameter requiring the Data Type field to be set to “REAL” when creating the
controller tag. To read a 32-bit integer parameter, set the tag Data Type field to “DINT.” For a 16-bit parameter, set the Data Type field to “INT.” See
the drive documentation to determine the size of the parameter and its data type.