Using Explicit Messaging
6-11
PowerFlex 750-Series Drive DeviceNet Option Module User Manual
Publication 750COM-UM002A-EN-P
ControlLogix – Formatting a Message to Write Multiple Parameters
Figure 6.11 Scattered Write Multiple Message Configuration Screens
The following table identifies the data that is required in each box to
format a multiple write message.
Configuration Tab
Example Value
Description
Message Type
Service Type
(1)
Service Code
Class
Instance
Attribute
Source Element
Source Length
Destination
CIP Generic
Custom
4e (Hex.)
93 (Hex.)
0 (Dec.)
0 (Hex.)
Scattered_Write_Request
(3)
40 bytes
Scattered_Write_Response
(4)
Used to access Parameter Object in the Option Module.
Required for scattered messages.
Code for the requested service.
Class ID for the DPI Parameter Object.
Required for scattered messages.
Required for scattered messages.
Name of the tag for any service data to be sent from
scanner to the Option Module/drive.
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
(2)
My_DeviceNet_Scanner
The path is the route that the message will follow.
Tag Tab
Example Value
Description
Name
Scattered_Write_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 selecting a Service Type other than “Custom” from the pull-down menu, an appropriate Hex. value is automatically
assigned to the Service Code box which grays out (unavailable). When writing to 32-bit REAL (floating point) parameters, as in this
example, data conversion using COP (Copy) instructions or UDDT’s is required to correctly write the parameter values.
(2)
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_DeviceNet_Scanner). Then always type in a comma followed by a “2” which is the DeviceNet scanner port, followed by
another comma, and then the node of the drive (for this example, “1”).
(3)
In this example, we are writing to five 32-bit REAL (floating point) parameters. Each parameter being written to requires two
contiguous DINT registers. Therefore, a controller tag was created with its Data Type field set to the name of the UDDT of five
interleaved DINTs and REALs. Also, the Source Length field on the Message Configuration screen must correspond to the
selected Data Type in bytes (for this example, 40 bytes for an array of five scattered real structures. Scattered write messages
always assume that every parameter being written to is a 32-bit parameter, regardless of its actual size. Maximum message length
is 128 bytes which can write up to 16 parameters, regardless of their size
(4)
The controller tag for “Scattered_Write_Response” must be the same size as the controller tag for “Scattered_Write_Request.”
Summary of Contents for PowerFlex 750-Series
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