Mitsubishi Electric FR-F820-00046, Instruction Manual

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Parameters Ethernet communication (FR-F800-E)
FR-F800 5 - 579
Communication procedure
●
Using TCP/IP
The following is the communication procedure when executing SLMP communication with TCP/
IP. With TCP/IP, connections are established when communication is executed, and whether data
is received normally or not is checked to ensure reliability of data. However, the line load is high
as compared to UDP/IP.
I003116E
Fig. 5-281: Communication procedure when executing SLMP communication with TCP/IP
The external device issues a connection request
to the inverter. (Active open)
External device
Inverter
Connection request Connecting operation
Sending a request message Execution of the operation
Receiving the response message Returning a response message
Closing the connection Closing the connection
The process is repeated as needed.
The inverter accepts the connection request
from the external device. (Passive open)
Upon establishment of the connection, the
external device sends a request message to the
inverter. According to the request message sent from the
external device, the inverter executes a reading,
writing, or other operation.
The external device receives the response
message from the inverter and confirms the
operation result. Upon completion of the operation, the inverter
sends a response message to the external
device.
The external device issues a close request to the
inverter and closes the communication. The inverter accepts the close request from the
external device and closes the communication.