69
Computing the Cycle Time
Section 2-7
Scheduled Interrupt Tasks
The interrupt response time of scheduled interrupt tasks is the time taken
from after the scheduled time specified by the MSKS(690) instruction has
elapsed until the interrupt task has actually been executed. The length of the
interrupt response time for scheduled interrupt tasks is 1 ms max. There is
also an error of 80
μ
s in the time to the first scheduled interrupt (0.5 ms min.).
Note
Scheduled interrupt tasks can be executed during execution of the user pro-
gram (even while an instruction is being executed by stopping the execution of
an instruction), I/O refresh, peripheral servicing, or overseeing. The interrupt
response time is not affected by which of the above processing operations
during which the scheduled interrupt time occurs. Scheduled interrupts, how-
ever, are not executed during execution of other interrupt tasks even if the
interrupt conditions are satisfied. Instead, the interrupts are executed in order
of priority after the current interrupt task has completed execution and the
software interrupt response time has elapsed.
2-7-9
Serial PLC Link Response Performance
The response times for CPU Units connected via a Serial PLC Link (master to
slave or slave to master) can be calculated as shown below. If a PT is in the
Serial PLC Link, however, the amount of communications data will not be
fixed and the values will change.
• Maximum I/O response time (not including hardware delay) =
Master cycle time + Communications cycle time + Slave cycle time + 4 ms
• Minimum I/O response time (not including hardware delay) =
Slave communications time + 0.8 ms
Here,
Software interrupt response time
Internal timer
Scheduled interrupt task
Scheduled interrupt time
Number of partici-
pating slave nodes
The number of slaves to which links have been established
within the maximum unit number set in the master.
Number of non-par-
ticipating slave
nodes
The number of slaves not participating in the links within the
maximum unit number set in the master
Communications
cycle time (ms)
Slave communications time
×
Number of participating slave
nodes + 10
×
Number of non-participating slave nodes
Slave communica-
tions time (ms)
• Communications time set to Standard
0.4 + 0.286
×
((No. of 1)
×
No. of link words
×
2 + 12)
• Communications time set to Fast
0.4 + 0.0955
×
((No. of 1)
×
No. of link words
×
2 +
12)
Summary of Contents for CP1L-EL20DR-D
Page 3: ...CP1L EL20D CP1L EM30D CP1L EM40D CP1L EL EM CPU Unit Operation Manual Produced July 2017...
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Page 22: ...xxii...
Page 34: ...xxxiv Software Licenses and Copyrights 7...
Page 192: ...158 Trial Operation and Debugging Section 5 3...
Page 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Page 666: ...632 Trouble Shooting Section 11 7...
Page 696: ...662 Standard Models Appendix A...
Page 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Page 836: ...802 PLC Setup Appendix G...
Page 838: ...804 TCP Status Transitions Appendix H...
Page 840: ...806 Ethernet Network Parameters Appendix I...
Page 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Page 844: ...810 Ethernet Specifications Appendix K...
Page 851: ...Index 817 work words 118 write protection 447...
Page 852: ...818 Index...
Page 854: ...820 Revision History...
Page 855: ......