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3.3 Settings for Creation and Execution of Multiple Sequence Programs
3.3.3 Low speed execution type program
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SEQUENCE PROGRAM CONFIGURATION AND
EXECUTION CONDITIONS
POINT
When a low speed execution type program and an initial execution type program
are to be executed, the low speed execution type program is executed after
completion of the initial execution type program(
In that case, set a value greater than the sum of the execution times of the initial
execution type program and low speed execution type program as the initial
execution monitoring time.
(3) Precautions for low speed execution type program creation
(a) Low speed program execution time setting
Setting the low speed program execution time increases the scan time since the
set length of the time is secured.
Set the low speed program execution time or increase the WDT setting to make
the scan time shorter than the WDT.
(b) Unavailable instruction
The COM instruction is not available for low speed execution type programs.
(c) Execution timing
Low speed execution type programs are executed even during the scan where the
initial execution type program has been executed.
To prevent low speed execution type programs from being executed after the
initial execution type program execution, provide interlocks with the special relays
(SM402, SM403).
(d) Setting range
Set only either the constant scan time or the low speed program execution time.
When both the constant scan time and the low speed program execution time are
set, "PRG. TIME OVER (error code: 5010)" occurs under the condition of (excess
time of constant scan) < (low speed program execution time).
(e) Index register at program switching
Refer to Section 10.6.3 for the index register processing performed when a scan
execution type program is switched to a low speed execution type program.
Refer to Section 10.6.4 for the index register processing performed when an
interrupt program/fixed scan execution type program is executed during execution
of a low speed execution type program.