Rockwell Automation 20-COMM-Q ControlNet Adapter User Manual
Page 152
6-24
Using Explicit Messaging
20-COMM-C/Q ControlNet Adapter User Manual
Publication 20COMM-UM003F-EN-P
PLC-5 Controller – Formatting a Message to Read a Single Parameter
Figure 6.27 Read Single Message Configuration Screen
The following table identifies the data that is required in each box to
configure a message to read a single parameter.
General Tab
Example Value
Description
Communication Command
Service Code
Class Number
Instance Number
(1)
Attribute Number
PLC-5 Data Table Address
Size in Elements
Port Number
Local ControlNet Node
CIP Generic
e (Hex.)
93 or 9F (Hex.)
(2)
3 (Hex.)
9 (Hex.)
N40:0
(3)
2
(3)
2
2
Command type for controller to read data from the drive.
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.
An unused controller data table address containing the message
instruction. This address is the starting word of the destination file.
Number of elements (words) to be transferred. Each element size is a
16-bit integer.
Controller port to which the network is connected.
The node address of the adapter connected to the drive.
(1)
The instance is the parameter number in the drive (Port 0). To read a parameter in another port, see
DPI Parameter Object on page C-16
(Class code 0x93) or
Host DPI Parameter Object on page C-30
(Class code 0x9F) to determine the instance number. For example, to read
parameter 4 of a peripheral in Port 5 of a PowerFlex 750-Series drive, the instance would be 21504 + 4 = 21508 or 5404 (Hex).
(2)
See
Table 6.A on page 6-2
for limitations of PowerFlex 7-Class and PowerFlex 750-Series drives when using DPI Parameter Object Class
code 0x93 or Host DPI Parameter Object Class code 0x9F for explicit messaging.
(3)
In this example, Output Current is a 32-bit integer parameter requiring the Size in Elements field to be set to ‘2’. If the parameter being
read is a 16-bit integer, the Size in Elements must be set to ‘1’. When using a PowerFlex 700S or PowerFlex 750-Series drive, Output
Current is a REAL (floating point) parameter. You must still write this data to an integer file with Size in Elements set to ‘2’. The following
page shows ladder logic to convert the data into a floating point.