Active Open Procedure - Mitsubishi Melsec-L Series User Manual

7.2.3

Active open procedure

Active open is a connection method that performs an active open process on a connected device in Passive open wait
status. The procedure that the E71 performs an Active open process is as follows. For the OPEN/CLOSE instructions,
refer to "DEDICATED INSTRUCTIONS". (
Open/close processes for the connection number 1
Ex.
Open status
Open allowed status
(closed)
Closed status
Initial normal completion
signal X19
OPEN instruction
OPEN instruction
completion device
OPEN instruction
completion device + 1
Open abnormal detection
signal X18
CLOSE instruction
CLOSE instruction
completion device
CLOSE instruction
completion device + 1
Open completion signal
(address: 5000
H
Open request signal
(address: 5002
H
Page 155, CHAPTER 13)
Parameter communication
Power-on completed
1
)
)
CHAPTER 7 COMMUNICATION PROCEDURE
2
1 scan
Abnormally ended
5
ACK
SYN
3
SYN + ACK
4
Abnormally ended
1 scan
Abnormally
ended
ACK
FIN
7
6
FIN + ACK
7
73