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CHAPTER 3 CPU MODULE FUNCTIONS
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3.6 Service Processing Setting
(c) Specify service process execution counts
Operation when 1 time is set is as shown below.
Operation when 2 times is set is as shown below.
● When several devices are connected to one CPU module, each device requests service processing. When the CPU
module simultaneously receives requests from several devices, a single END processing can simultaneously accept
several requests if the service processing count is set to the number of connected devices. This improves response
performance. Note that the scan time increases by the amount of service processing time.
● If no request data for service processing exists, END processing speeds up by the amount of request processing time.
(The CPU module does not wait for requests.)
Program execution
END processing
Request 1)
Program execution
END processing
Request 2)
Program execution
END processing
Request 3)
Peripheral
Regardless of request data size, one
request is processed at one END processing.
Even if the program execution time is the same,
the scan time depends on service processing time.
Request 1)
Request 2)
Request 3)
Request 4)
Request 5)
1st scan
2nd scan
3rd scan
Program execution
END processing
Request 1)
Program execution
END processing
Request 2)
Request 3)
Peripheral
Request 4)
Regardless of request data size, two requests
are processed at one END processing.
Request 1)
Request 2)
Request 3)
Request 4)
Request 5)
1st scan
2nd scan