6-18
Using Explicit Messaging
PowerFlex® 755 Drive Embedded EtherNet/IP Adapter User Manual
Publication 750COM-UM001A-EN-P
PLC-5 Reading/Writing Multiple Parameters
You can read or write only contiguous parameters. Scattered read/write
messaging is not supported. Also, the range of contiguous parameters
must be contained in the same N-File. Two elements (words) are
required for each parameter being read or written. For example, to read
5 contiguous parameters, 10 elements (words) must be used.
SLC 500 Example
When using RSLogix 500 v7.10 or lower, explicit messaging must be
performed using the PCCC N-File method. For RSLogix 500 v7.20 or
higher, the CIP messaging method has been added along with the PCCC
N-File method. However, it is recommended to use the CIP method
because it is easier to use and understand. For this reason, only
instructions for the CIP method are provided. If you must use the PCCC
N-File method, refer to the
The CIP messaging method provides a Generic Get/Set Attribute
Service which can be used to perform single parameter read or write
and multiple parameter read or write explicit messages. Also, the
Generic Set Attribute Service offers the choice of writing the data to the
drive’s Non-Volatile Storage (NVS) or the drive’s Random Access
Memory (RAM). Note that when selecting the data to be written to
RAM, the data will be lost if the drive loses power.
For supported classes, instances, and attributes, refer to
SLC 500 Example Ladder Logic Program to Read Single Parameter
A Generic Get Attribute Single message is used to read a single
parameter. This read message example reads the value of the 32-bit
REAL (floating point) parameter 007 - [Output Current] in a PowerFlex
750-Series drive.
Figure 6.21 Example Ladder Logic Explicit Messaging Program for Read Single
