Tcp/Ip Communications; Establishing A Connection - Mitsubishi Electric QJ71E71-100 User Manual

7.2

TCP/IP Communications

This section describes TCP/IP communications.
7.2.1

Establishing a connection

TCP/IP communications require establishing connections between communication devices. When the server-side
device is in standby status after performing a Passive open process, a connection is established after the client-side
device issues an open request (Active open process) to the server and a response is received.
In TCP/IP communications, the system establishes a connection and checks whether each data has arrived at the
recipient normally, thereby ensuring data reliability. Compared to UDP/IP communications, however, TCP/IP places a
greater load on the line.
When the E71 is in Passive open status
Ex.
88
Server
E71
Passive open
(passive)
Open request
Response
Connected device
Connection
Client
Active open
(active)