Rockwell Automation 20-COMM-D DeviceNet Adapter Series B FRN 2.xxx - Manual (Page 142)

6-14 Using Explicit Messaging
20-COMM-D DeviceNet Adapter User Manual
Publication 20COMM-UM002G-EN-P
ControlLogix Controller – Formatting a Message to Read Multiple Parameters Using
RSLogix 5000 Software, Any Version
Figure 6.13 Scattered Read Message Configuration Screens
The following table identifies the data that is required in each box to
configure a message to read multiple parameters.
Configuration Tab Example Value Description
Message Type
Service Type (1)
Service Code (1)
Class
Instance
Attribute
Source Element
Source Length
Destination
CIP Generic
Custom
4b (Hex.)
93 (Hex.)
0 (Dec.)
0 (Hex.)
Scattered_Read_Request_
Internal _Use_Only[0] (3)
31 (3)
Scattered_Read_Response[0]
Used to access Parameter Object in the adapter.
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 or bridge to the adapter/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_Bridge The path is the route that the message will follow.
Tag Tab Example Value Description
Name Scattered_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) 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_Bridge). Then always type in ‘2’ which is the DeviceNet scanner port, followed by a comma, and then the node of the
drive (for this example, ‘1’).
(3) In this example, we are reading five parameters. Each parameter being read requires an array of three INT registers. Therefore, a
controller tag was created with its Data Type field set to ‘INT[15]’. Also, the Source Length field on the Message Configuration screen
must correspond to the selected Data Type in bytes (for this example, 31 bytes total; 30 bytes for an INT[15] array plus one extra
required byte that is always set to zero). Scattered read messages always assume that every parameter being read is a 32-bit integer,
regardless of its actual data type. Maximum length is 133 bytes; 132 bytes or 66 words which equates to 22 parameters plus one
extra required byte.