Yaskawa DeviceNet Option Card CM059 - Manual (Page 45)

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DeviceNet Explicit Messaging Communications
The DeviceNet communications may also be accomplished by utilizing an “Explicit Message” to communicate with the
master PLC or controller. The Explicit messaging communications is performed differently than Polled I/O type messaging in
that commands are not sent cyclically in the scan of the controlling master, but one message is sent and one response is
received. See table below for details on Explicit Message Format.
The following pages define the supported DeviceNet implemented objects and services for the drive option.
Table 22: Explicit Message Format
Header MAC ID Service Code Class Instance Attribute Data Footer
Item Description
Header Since it is automatically set, there is no need to do anything.
MAC ID Master/slave MAC ID is input for communication.
Service Code
Code, which shows data write/read, is input in the requested message.
Also, the requested service code MSB (the most significant bit) inputs “1” at normal
response, and “94” at fault.
Example:
0E: Read request 8E: Read normal response
10: Write request 90: Write normal response
94: Fault response
Class
Each function of DeviceNet is classified by three codes.
When you wish to designate data, use these 3 codes to do so.
Instance
Attribute
Data
Request: Write data is input.
Response: Read data and error code are input.
Footer Since it is automatically set, there is no need to do anything.