Overview Of Messages And Responses; Command Format; Response Format; Normal Response - Omron 3G3MV-PDRT2 User Manual

Message Communications
6-3

Overview of Messages and Responses

When message communications are used, the Inverter's DeviceNet Communications Unit/Card
returns responses as explained below.
Basically, DeviceNet communications are executed in 1-byte (8-bit) units. In the case of single-word
data (16 bits), the rightmost bits (least significant) and the leftmost bits (most significant) are
reversed in order due to the following reasons:
• Data on communications line is transmitted in the order of rightmost bits and leftmost bits.
• Data that is internally processed by PLC for issuing commands is transmitted in the order of left-
most bits and rightmost bits.
Therefore, reverse the order for attributes where "Word" is written in the "Size" column in the tables
on subsequent pages and create attached data or read response data.
Note There is no need to take this into consideration for remote I/O because the rightmost bits and
leftmost bits are automatically reversed.

Command Format

■
28 28 01 01
Command code
(FINS command for
PLC)

Response Format

■
●

Normal Response

28 28 01 01
Command code
(FINS command for PLC)
● Error Response
28 28 01 01
Command code
(FINS command for PLC)
● Failure or Timeout during Transmission
28 28 01 01
Command code
(FINS command for PLC)
Destination Service
node
Code
address
00 00
Number of bytes
Completion code
transmitted
00 00
Completion
Number of bytes
code
transmitted
Completion code
(FINS error code)
Class ID Instance ID
Destination
node
address
Destination
node address
Chapter 6
32 bytes max.
Service Data
Service data (attribute
No. or attribute No. and
write data)
32 bytes max.
Service
Service data
Code (read data)
94
2 bytes
Service Error Code
Code
6-7