90
Computing the Cycle Time
Section 2-7
2-7
Computing the Cycle Time
2-7-1
CPU Unit Operation Flowchart
The CPU Unit processes data in repeating cycles from the overseeing pro-
cessing up to peripheral servicing as shown in the following diagram.
NO
YES
Power ON
Checks Unit connection status.
Checks hardware and user
program memory.
Executes user program (i.e.,
executes READY cyclic tasks).
Waits until the set cycle time
has elapsed.
Calculates cycle time.
Sets error flags.
Performs I/O refreshing.
Services peripheral devices.
Peripheral
servicing
I/O
refreshing
Cycle time
calculation
Program
execution
Overseeing
processing
PLC
cycle
time
Startup
initialization
Check OK?
ERR/ALM
indicator ON or
flashing?
End of program?
Flashing
(nonfatal error)
ON (fatal error)
Error
Normal
Содержание CP1H-CPU - 05-2006
Страница 1: ...OPERATION MANUAL CP1H CPU Unit SYSMAC CP Series CP1H X40D CP1H XA40D CP1H Y20DT D Cat No W450 E1 02...
Страница 2: ...CP1H X40D CP1H XA40D CP1H Y20DT D CP1H CPU Unit Operation Manual Revised May 2006...
Страница 3: ...iv...
Страница 11: ...xii TABLE OF CONTENTS...
Страница 15: ...xvi...
Страница 19: ...xx...
Страница 31: ...xxxii Conformance to EC Directives 6...
Страница 71: ...40 Function Blocks Section 1 5...
Страница 133: ...102 Computing the Cycle Time Section 2 7...
Страница 169: ...138 CPM1A Expansion I O Unit Wiring Section 3 6...
Страница 411: ...380 Clock Section 6 8...
Страница 519: ...488 Replacing User serviceable Parts Section 10 2...
Страница 527: ...496 Standard Models Appendix A...
Страница 535: ...504 Dimensions Diagrams Appendix B...
Страница 628: ...597 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Страница 629: ...598 Connections to Serial Communications Option Boards Appendix F...
Страница 659: ...628 PLC Setup Appendix G...
Страница 665: ...634 Index work words 159 write protection 370...
Страница 667: ...636 Revision History...