Rockwell Automation 1769-SM2 Compact I/O DSI/Modbus Communication Module - Manual (Page 65)

Chapter
5
Understanding Explicit Messaging
This chapter provides information about explicit messaging.
Explicit messaging is used to read/write data that is not part of the
module’s I/O Image (
Chapter 4 ), such as:
•
Reading/writing drive parameters.
•
Operating as a Modbus RTU Master and initiating Request/Response
messages to Modbus RTU Slave devices, such as PowerFlex 7-Class
drives with 20-COMM-H adapters.
The following table shows various products that can be used with the
1769-SM2 module and whether they support explicit messaging:
Contact your local Rockwell Automation, Inc. representative for
inquiries about the explicit message capabilities of products not
specified above.
Topic Page
Formatting Explicit Messages 5-2
Modbus RTU Master Operation Messages 5-9
Products
Supports Explicit Messaging
Yes No
MicroLogix 1500 LRP Series A and B, and
LSP processors ✔
MicroLogix 1500 LRP Series C (or newer) and
RSLogix 500 v6.30 (or higher)
Important: This LRP processor supports messaging
only for the first two I/O modules capable of messaging.
✔
RSLogix 500 versions prior to v6.30 ✔
Enhanced CompactLogix processors such as the -L31,
-L32E, and -L35E ✔
CompactLogix -L20 and -L30 processors ✔
1769-ADN DeviceNet adapter (see documentation for
possible future explicit messaging support) ✔
!
ATTENTION: Hazard of equipment damage exists. If Explicit
Messages are programmed to write parameter data to Non-Volatile
Storage (NVS) frequently, the NVS will quickly exceed its life cycle
and cause the drive to malfunction. Do not create a program that
frequently uses Explicit Messages to write parameter data to NVS.