Toshiba V Series, User Manual

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Appendix F Socket Interface
Transmission Processing Time
The send/receive processing times (for the S controller and the EN311) in socket
transmission can be determined from the following formulas.
Conditions:
(1) Only one socket is used in the EN311.
(2) The user program execution time itself is not included.
(3) The processing times are given for data size ranges for which no packet division
occurs. The size ranges for which packet division does not occur are:
• UDP:1 to 736 words
• TCP:1 to the maximum receivable segment size determined when the connection
was established.
• UDP send processing time (from USEND_T instruction activation to EN311 trans-
mission completion)
(UDP USEND_T processing time) = 7.28 (ms) + 0.0181 (ms)
×
(number of words
transferred)
• UDP reception processing time 1:Reception request issued first type
From the start of EN311 reception to completion of URCV_T instruction execution
(UDP reception processing time 1) = (S controller scan time) + 8.35 (ms) +
0.000820 (ms)
×
(number of words transferred)
• UDP reception processing time 2:Socket status monitoring type
From URCV_T instruction activation to instruction completion (when EN311 data
reception has completed)
(UDP reception processing time 2) = (S controller scan time) + 0.402 (ms) +
0.0056 (ms)
×
(number of words transferred)
• TCP USEND_T processing time (from USEND_T instruction activation to EN311
transmission completion)
(TCP USEND_T processing time) = 7.23 (ms) + 0.0174 (ms)
×
(number of words
transferred)
• TCP reception processing time 1:Reception request issued first type
From the start of EN311 reception to completion of URCV_T instruction execution
(TCP reception processing time 1) = (S controller scan time) + 14.3 (ms) + 0.105
(ms)
×
(number of words transferred)
• TCP reception processing time 2:Socket status monitoring type
From URCV_T instruction activation to instruction completion (when EN311 data
reception has completed)
(TCP reception processing time 2) = (S controller scan time) + 0.384 (ms) +
0.0056 (ms)
×
(number of words transferred)
Usage Recommendations
• There are cases where the transmission delay time will be longer than the calculated value
due to details of the actual environment used. Factors that can cause the transmission delay
time to increase include network load, EN311 load, and the S controller operating state.