Compactlogix example scattered write request data, Compactlogix example scattered write response data – Rockwell Automation 25-COMM-D PowerFlex 525 DeviceNet Adapter User Manual
Page 67
Rockwell Automation Publication 520COM-UM002A-EN-E - April 2013
67
Using Explicit Messaging
Chapter 6
CompactLogix Example Scattered Write Request Data
In this message example, we use the source tag (Scattered_Write_Request) to
write new values to these 16-bit parameters:
DPI Parameter Object on page 117
(Class code 0x93) for parameter
Example Scattered Write Request Converted Data on page 67
shows
the parameter values.
Example Scattered Write Request Converted Data
CompactLogix Example Scattered Write Response Data
The results of the message appear in the destination tag named
Scattered_Write_Response (
Example Scattered Write Response Data on
). Values of “0” indicate no errors occurred.
Path
(3)
DeviceNet_Scanner, 2, 1
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 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) Scattered writes always write parameter values to the drive’s Non-Volatile Storage (EEPROM) memory, so these values will remain
even after the drive is power cycled. Important: 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 Host parameter
C121 [Comm Write Mode] to 1 “RAM only”.
(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,
DeviceNet_Scanner). Then always type in a comma followed by a “2”, which is the DeviceNet scanner port, followed by another
comma, then followed by the DeviceNet node number of the drive (for this example, “1”).
(4) See
Explicit Messaging Class Code Compatibility with PowerFlex 525 Drives on page 55
for limitations of PowerFlex 525 drives when
using DPI Parameter Object Class code 0x93 for explicit messaging.
(5) In this example, we are writing to five 16-bit parameters. Each parameter being written to requires two contiguous INT registers.
Also, the Source Length field on the Message Configuration screen must correspond to the selected Data Type in bytes (for this
example, 20 bytes for an array of ten INTs). Scattered write messages always assume that every parameter being written to is a 16-
bit parameter, regardless of its actual size. Maximum message length is 256 bytes which can write up to 64parameters, regardless of
their size. For parameter numbering, see
DPI Parameter Object on page 117
(6) The controller tag for “Scattered_Write_Response” must be the same size as the controller tag for “Scattered_Write_Request” (for
this example, 20 bytes). An array of INTs is suggested to be able to read any error codes that are returned.
PowerFlex 525 Drive Parameters
Write Value
A442 [Accel Time 2]
11.10 Sec
A443 [Decel time 2]
22.20 Sec
A415 [Preset Freq 5]
33.30 Hz
A416 [Preset Freq 6]
44.40 Hz
A417 [Preset Freq 7]
55.50 Hz
Configuration Tab
Example Value
Description