Mitsubishi Electric MELSEC Q Series User Manual page 203

(2) Precautions
(a) Checking by KeepAlive
The same as user Ethernet port (CH1 and CH2).
(Page 193, Section 12.1 (2)(a))
(b) Resend processing for TCP connections
Resend processing for TCP connections When there is no ACK response of the TCP protocols from the
external device for sending in TCP connection, resend processing is performed at the following numbers of
resends and resend intervals.
After the final resend, if there is no ACK response of the TCP protocol within 64n seconds, the connection will
be disconnected as an external device error.
Number of
resends
First
Second
Third
Fourth
Fifth
Sixth
Seventh
Eighth
Ninth
Tenth
Eleventh
Twelfth
*1 : The variable n is a coefficient calculated dynamically based on the external device
and network status.
*2 : After 30 seconds, destination device error is assumed and the connection is
released even if the number of resends does not reach to 12 times.
(c) Connection not covered by the operation assurance
Operations of the following commercial connection devices are not assured. Customers need to confirm the
operation before using it.
• Connection using the Internet (a general public line)
• Connection using firewall devices
• Connection using broadband routers
• Connection using wireless LAN
CHAPTER 12 FUNCTIONS ACCESSED VIA ETHERNET PORTS
Interval until resend
When connection is being
*1 *2
established
n seconds
n seconds
n seconds
n seconds
n seconds
2n seconds
4n seconds
8n seconds
16n seconds
32n seconds
64n seconds
64n seconds
After connection is
*1
established
n seconds
2n seconds
4n seconds
8n seconds
16n seconds
32n seconds
64n seconds
64n seconds
64n seconds
64n seconds
64n seconds
64n seconds
12
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