Appendix C Explicit Messages; Basic Format Of Explicit Messages - Omron GRT1-PNT - DATASHEET 2 Operation Manual

C-1

Basic format of explicit messages

Destination station address
Service code, Class ID,
Instance ID, Attribute ID
Data
Response blocks
Number of bytes received
Source station address
Explicit messages sent from the Controller Unit to a GRT1 Series PROFINET
IO Communication Unit can be used to read or write any parameter of a
specified GRT1 Series PROFINET IO Communication Unit.
The PROFINET IO Communication Units process the commands sent from
the Controller and then return responses.
The basic format of each command and response is shown below.
/i
Command Block
Destination station
address
The station address of the Unit that is sending the explicit messages
(commands) is specified as a single-byte hexadecimal number.
The parameters used for specifying the command, processing object, and
processing content.
Note The number of bytes designated for Class ID, Instance ID, and Attribute ID depend on
the Controller Unit. When sent from an OMRON Controller, the Class ID and Instance
ID are 2 bytes (4 digits), and Attribute ID is 1 byte (2 digits).
Data is not required when the Read command is used.
/i
Normal Response Block
Number of bytes received
/i
Error Response Block
Number of bytes received:
0004 Hex (fixed)
The number of bytes received from the source station address is returned in
hexadecimal. When an error response is returned for an explicit message, the
number of bytes is always 0004 Hex.
The station address of the Unit from which the command was sent is returned
in hexadecimal.
Appendix C
Explicit messages
Service Class Instance
code ID ID
Source station address
Source station address
Attribute Data
ID
Service code Data
Service code Error code
93