Appendix; Cyclic Transmission - Mitsubishi Electric MR-J5-G User Manual

2.4

APPENDIX

Cyclic transmission

Outline
In CC-Link IE Field Network Basic, the command sent from the master station (controller) to the slave station (servo amplifier)
is called a request message, and the command sent from the slave station (servo amplifier) to the master station (controller)
is called a response message.
The master station (controller) sends the request message to all slave stations (servo amplifiers) by directed broadcast. When
a servo amplifier receives a request message, it acquires the data addressed to its own station and returns the response
message to the master station (controller) by unicast after the response time of the servo amplifier has passed. The servo
amplifier response time varies depending on the command to be sent.
A link device (RWr, RWw, RX, RY) is used for data communications, and the master station (controller) refreshes the link by
sending and receiving request messages and response messages at regular intervals. The servo amplifier uses the received
data in the object dictionary to drive the servo motor and return monitor data.
Request message (directed broadcast)
Master station
(controller)
Response message (unicast)
Message format
The request message sent from the master station (controller) and the response message returned from the slave station
(servo amplifier) are sent in the following message format.
The message uses UDP/IP.
The PDO uses RWw and RWr. The RPDO (command) uses the request message (RWw), and the TPDO (feedback) uses the
response message (RWr).
• Request message format
Ethernet IP UDP
header header header
• Response message format
Ethernet IP UDP
header header header
Constant cycle
CCIEF
Command,
Basic
etc.
header
CCIEF Slave station
Basic notification
header information
Slave station
(servo amplifier)
Link device (for 16 stations)
(RY, RWw)
Link device
(RX, RWr)
2 CC-Link IE Field Network Basic
2
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2.4 APPENDIX