Omron CJ Series - Overview

6 Message Communications
6-2
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
6-1 Overview
Message communications enable messages to be sent between nodes on a PROFIBUS network when
required by system conditions. It is possible for messages to be sent between a CPU and a PROFIBUS
Master or Slave Unit. You can use them to send/receive data; read time data, error logs, and other data;
or control specific operation, e.g., clearing the error log.
There are three types of messages:
• Explicit
• PROFIBUS
• Other
The figure below depicts the command structure for the CJ1W-PRM21 PROFIBUS Master units
CPU Unit PROFIBUS Master Unit
PROFIBUS network
PROFIBUS message
SendCmd
Instruction
(2801 Hex)
2801 Explicit message
SendCmd
Instruction
(2809 Hex)
2809 PROFIBUS message
SendCMd
Instruction
Other message
DP-V1 Explicit message
(0101 Hex)
(2103 Hex)
Other
message
function
PROFIBUS
message
function
Explicit
message
function