Mitsubishi FX3U-ENET, User Manual

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MELSEC-F
5 COMMUNICATION PROCEDURE
(1) Timer setting – TCP ULP timer (BFM#4)
(a) This item sets the time of packet existence during TCP data sending.
This timer is passed through the parameter when TCP opens or data is
sent.
(b) Set the value in the range from 2 to 32767.
(c) Timer setting = setting value
×
500 ms
(2) Timer setting - TCP zero window timer (BFM#5)
(a) The window indicates the reception buffer on the receiving side.
(b) When there is no more space in the receiving buffer (window size = 0) on
the receiving side, data communication has to wait until enough space is
made.
When this occurs, the sending side sends a sending window confirmation
packet to the receiving side after the TCP zero window timer value has
been reached, and confirms the reception enabled status.
(c) Set the value in the range from 2 to 32767.
(d) Timer setting = setting value
×
500 ms
(3) Timer setting – TCP resend timer (BFM#6)
(a) Set the resend time if ACK is not returned during TCP opening or data
transmission. This timer is also used for the existence time of the ARP
function.
(ARP is resent in "TCP resend timer" value/2 if a response is not returned
after the sent ARP request.)
It also serves as the minimum setting time for the data link instruction
arrival monitoring time.
(b) Set the value in the range from 2 to 32767.
(c) Timer setting = setting value
×
500 ms
(4) Timer setting – TCP end timer (BFM#7)
(a) When the TCP connection is closed from the local station, this timer sets the
monitoring time for how long the local station waits for a FIN request from
an external device after it sends a FIN request and the external device
returns an ACK.
(b) If the FIN request cannot be received from the external device before the
time designated by the TCP end timer setting, a RST should be sent to the
external device to forcibly close the connection.
(c) Set the value in the range from 2 to 32767.
(d) Timer setting = setting value
×
500 ms