Explicit Messages Basic Format - Omron E5AR User Manual

Overview of Explicit Message Communications
Sending Explicit Messages Specific to DeviceNet-compatible Digital Controllers
5-1-3

Explicit Messages Basic Format

Command Block
Response Block
■ CompoWay/F Binary Commands
CompoWay/F binary commands are CompoWay/F communications com-
mands expressed in hexadecimal, and are easy to execute from ladder pro-
grams. CompoWay/F communications commands that include ASCII data,
however, cannot be sent or received. Therefore, Read Controller Attribute (05
03) and broadcasting (unit number = XX) cannot be used.
■ CompoWay/F ASCII Commands
CompoWay/F ASCII commands are CompoWay/F communications com-
mands expressed in ASCII, so numerical values must be converted to ASCII
when executing these commands from a ladder program. CompoWay/F
binary commands cannot be used. Broadcasting (unit number = XX) cannot
be used, but all other CompoWay/F communications commands can be sent
and received, including Read Controller Attribute (05 03), which cannot be
used with CompoWay/F binary commands.
The master can send explicit messages to a DeviceNet-compatible Digital
Controller to control various operations supported only by DeviceNet-compat-
ible Digital Controllers and to read DeviceNet-specific settings and status
information.
These explicit messages are used to read and write maintenance information
specific to DeviceNet-compatible Digital Controllers.
The basic formats of explicit message commands and responses are
described here.
Destination
Service
node
code
address
Destination Node Address
This parameter specifies the node address of the Controller to which the
explicit messages (commands) will be sent in single-byte (2-digit) hexadeci-
mal.
Service Code, Class ID, Instance ID, Attribute ID
These parameters specify the command type, processing target, and pro-
cessing details.
The Attribute ID does not need to be specified for some commands.
Data
Specifies the details of the commands, set values, etc. The data section is not
required for read commands.
The following format is used when a normal response is returned for the sent
explicit message.
No. of bytes Source node
received address
Class ID Instance ID Attribute ID
Service code Data
Section 5-1
Data
5-3