Mitsubishi Electric MELSEC iQ-R Series User Manual page 547

Active open procedure
Active open is a connection method that performs an active open processing in respect to an external device (Passive open)
that is in a passive open standby state for a connection. The following figure shows the process for the CC-Link IE TSN Plus
module to Active open.
For CONOPEN/CONCLOSE instructions, refer to the following.
 MELSEC iQ-R Programming Manual (Module Dedicated Instructions)
Ex.
Open/close processing for connection No.1
Power-on
Open status
Open enable status
(closed)
Closed status
'Initial status'
(Un\G6291480.0)
CONOPEN instruction
CONOPEN instruction
completion device
CONOPEN instruction
completion device +1
CONCLOSE instruction
CONCLOSE instruction
completion device
CONCLOSE instruction
completion device +1
'Open completion signal
(connection No.1)'
(Un\G6291456.0)
'Open request signal
(connection No.1)'
(Un\G6291464.0)
 After the module parameters are set, check that the initial processing for the CC-Link IE TSN Plus module has completed normally. ('Initial status'
(Un\G6291480.0): On)
 Start the open processing using the CONOPEN instruction.
 The CC-Link IE TSN Plus module executes open processing. (The module sends open request (SYN) to the external device.)
 Data can be exchanged after the open processing completes normally.
 Start the close processing using the CONCLOSE instruction. ('Open request signal (connection No.1)' (Un\G6291464.0): Off)
 The CC-Link IE TSN Plus module executes close processing. (The module sends close request (FIN) to external device.)
 Data communication ends when close processing completes normally.
*1 If RST is returned from the external device after SYN is sent from the CC-Link IE TSN Plus module, open abnormal completion occurs
immediately, and the open processing ends.
*2 If ACK or FIN is not returned even after the TCP end timer time, the CC-Link IE TSN Plus module forcibly cuts off the connection (sends
RST). (Close abnormal completion)
*3 If the open processing target port has not been linked up, the CONOPEN instruction will complete with an error. Execute the open
processing again after link-up, or check that 'Connection status' (Un\G2102344) is set to 1 before starting the open processing. If auto-
negotiation fails, the open processing will complete with an error. Retry the open processing after a while.
If the open processing completes with an error again, check the Ethernet cable connection or the operation of the external device and
switching hub.
Parameter
communications
completed


ACK
SYN

SYN + ACK

*3
('Open request signal (connection No.1)' (Un\G6291464.0): On)
*1
*2
Appendix 8 TCP/IP Communications, UDP/IP Communications
1 scan
Completed with an error

ACK
FIN


FIN + ACK
1 scan
A
Completed
with an error
APPX
545