Passive Open Procedure - Mitsubishi Electric QJ71E71-100 User Manual

7.2.4

Passive open procedure

The E71 has the following two connection methods for Passive open.
• Unpassive:
• Fullpassive:
Under the Passive open method, the open/close processes are performed using the procedures described below,
according to the Ethernet operation setting.
(1) When "Always wait for OPEN" is selected for the Ethernet operation setting
As the E71 is set to always wait for open, a connection is established when an Active open is requested from the
connected device. This eliminates the need for open/close processing programs on the E71 side.
Open status
Open enable status (closed)
(Active open acceptance enabled)
Closed status
Initial normal completion
signal X19
Open completion signal
(address: 5000
Open request signal
(address: 5002
92
Performs a passive open process on connections for all devices connected to the network,
regardless of the IP address and port number of the destination device.
Performs a passive open process on connections for the connected device specified by the IP
address and port number.
Parameter
communications
Power-on completed
1
)
H
)
H
*1
SYN + ACK
2
SYN
ACK
4
FIN + ACK
3
FIN
ACK