Mitsubishi Electric QJ71E71-100 User Manual page 236

(3) If a response message cannot be received from the connected device
If a response message cannot be received from the connected device (or if an error has been detected) using the
alive check function, the following processes are performed.
• The corresponding connection will be forcibly closed. (The line is disconnected.) Open the connection using
a user program again.
• Open completion signal is turned off, and the error code (C035
area.
Assuming that the values
Ex.
check at the timing shown in the figure below (an example of alive check using the PING command).
Open completion signal
(address: 5000 )
H
The last
communications
*1 The values of the number of retries and timers can be changed in the initial setting. (
234
*1
are set so that the number of retries may be three, the E71 performs an alive
Alive check
Destination
existence
Destination existence
confirmation
confirmation starting
interval timer
interval timer value
value
) is stored in the open error code storage
H
E71
Alive check Alive check
resent resent
(1st time) (2nd time)
Destination Destination
existence existence
confirmation confirmation
interval timer interval timer
value value
Connection
forced close
(error code: C035
Alive check
RST sending
resent
(TCP only)
(3rd time)
Destination
existence
confirmation
interval timer
value
Page 353, Appendix 4.1)
)
H