Instruction manual

94
 Explicit Message Communications
The DeviceNet-compatible Inverters can transfer explicit messages
(defined in DeviceNet specifications) to and from a DeviceNet master.
Various kinds of data can be set and referenced from the master, ranging
from DeviceNet-related settings to the Inverter’s control data. Unlike I/
O message communications, which are performed at regular intervals,
the explicit messages can be sent from the master at any time and corre-
sponding response messages will be returned.
• Format of Explicit Messages
Header MAC ID Service
Code
Class Instance Attribute Data Footer
Item Description
Header This value is set automatically, so there is no need
to check it.
MAC ID Contains the MAC ID of the master or slave that is
the other node involved in the data transfer.
Service
Code
In a request message, the service code specifies
the requested operation such as reading or writing
data.
In a normal response, bit 15 (the most significant
bit) of the request service code will be turned ON
in the response. If an error occurred, the code 94
will be returned.
Examples:
• 0E: Read request
• 8E: Normal read response
• 10: Write request
• 90: Normal write response
• 94: Error response
Class Each DeviceNet function is divided into these 3
codes. When specifying data, specify it with these
3 codes.
Instance
Attribute
Data Request: Contains the write data.
Response: Contains the read data or error code.