The CPM1A Cycle | Section | |
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5-2 The CPM1A Cycle
The overall flow of CPM1A operation is as shown in the following flowchart. The CPM1A is initialized internally when the power is turned on. If no errors are detected, the overseeing processes, program execution, I/O refreshing, and Peripheral Device servicing are executed consecutively (cyclically). The aver- age cycle time can be monitor from a Peripheral Device.
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| Power application |
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| Initialization processes |
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| Check hardware and |
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| Program Memory. |
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| No | Check OK? |
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| Yes |
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Set error flags and |
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| Preset cycle time |
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activate indicators. |
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| monitoring time. |
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| ALARM |
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ERROR or ALARM? | (flashing) |
| Execute user program. |
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ERROR |
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| End of program? | No |
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(lit) |
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| Yes |
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| Check cycle time set- |
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| ting. |
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| Minimum | No |
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| cycle time set? |
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| Yes |
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| Wait until minimum cycle |
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| time expires. |
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| Compute cycle time. |
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| Refresh input bits and |
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| output terminals. |
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| Service peripheral port. |
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Initialization
Overseeing processes
Program execution
Cycle time
Cycle time processing
I/O refreshing
Service peripheral port.
Note Initialization processes include clearing the IR, SR, and AR areas, presetting system timers, and checking I/O Units.
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