IDEC SmartAXIS Touch FT1A Series, User Manual

Page: 670 / 1232

1 Control Function Actions
12-2
SmartAXIS Touch User's Manual
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Output delay
There is a delay between an external output and the internal device Output(Q). The maximum delay period is
calculated by the amount of 300 milliseconds and the execution period.
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Control function
A control function refers to three processes: input refresh, ladder or FBD process, and output refresh.
For details of control function settings, refer to Chapter 3 “4 Special Functions” on page 3-45, and the “SmartAXIS
Ladder Programming Manual” or the "SmartAXIS FBD Programming Manual".
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Sleep
Sleep refers to the time used by the control function subtracted from the Execution Period. This is when the processor
executes HMI function.
■
Execution Period
The Execution Period refers to one scan of the control function (input r ladder or FBD p output
refresh) and HMI function (sleep).
The control function is executed once every specified execution interval.
■
HMI function
Parts laid out on the screen are processed from top to bottom only when the control function is in sleep mode.
Display processing pauses when execution of the next control function begins, and resumes when the function goes
to sleep again.
When processing reaches the bottom of the screen, processing returns to the top of the screen.
When an output occurs immediately after the output refresh
ends, the output delay will be the longest because the processor
waits for the output refresh in the next scan before reflecting
the output to the output relay.
Q
Q Output process
Input refresh
Output refresh
Ladder or FBD
process
Sleep
(HMI function
execution)
Input refresh
Output refresh
Ladder or FBD
process
Output delay
(maximum)
Output
External
output
Only control devices can be used for control function.
If execution of the control function takes more than half of the time specified for the Execution Period, the
processor automatically extends the Execution Period so that the control function completes within 1/2 of
the Execution Period. In this instance, error number 7 will be stored in HMI Special Data Register LSD53.
There is a delay in the ladder program or FBD program. Take this delay time into consideration when
specifying the Execution Period. For example, if it is necessary to capture external inputs within 100
milliseconds, set the Execution Period to 90 milliseconds. The default Execution Period is 10 milliseconds. If
you don't change the default value, it will be the same as the M8123 (10 milliseconds clock) operation
period. In this case, M8123 is always ON or OFF.