Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 383

Computing the Cycle Time
Peripheral Servicing Cycle
Time
Note
• Fixed cycle time setting in the PLC Setup
• File access in file memory, and the amount of data transferred to/from file
memory
• Fixed peripheral servicing time in the PLC Setup
The program execution cycle time is the total time required for the PLC to per-
form the 5 operations shown in the following tables.
Cycle time = (1) + (2) + (3) + (4) + (5)
Details
(1) Overseeing
(2) Program execution
(3) Cycle time calcula-
tion
(4) I/O refreshing
(5) Partial peripheral
servicing
The peripheral servicing execution cycle time depends on the following condi-
tions.
• Type and number of Special I/O Units, CS-series CPU Bus Units, Inner
Boards, and type of services being executed.
• Type and frequency of event servicing requiring communications ports.
• Use of peripheral and RS-232C ports
The peripheral servicing cycle time is the total time required for the PLC to
perform the 5 operations shown in the following tables.
Cycle time = (1) + (2)
Name
(1) Overseeing Checks user program memory,
processing checks for battery errors, etc.
(2) Peripheral Performs
servicing services for
the events
give at the
right, includ-
ing I/O
memory
access.
1. The cycle time display on a Programming Device is the Program Execution
Cycle Time.
2. The peripheral service cycle time varies with the event load and number of
Units that are mounted. In a Parallel Processing Mode, however, this vari-
ation will not affect the program execution cycle time.
I/O bus check, etc.
Same as for Normal Mode. Same as for Normal Mode.
Waits for the specified
cycle time.
Same as for Normal Pro-
cessing Mode.
Servicing file access
Processing
Events with CS-series
Special I/O Units (does
not include I/O refresh-
ing)
Events with CS-series
CPU Bus Units (does
not include I/O refresh-
ing)
Peripheral port events
RS-232C port events
Events with Inner
Boards
Events using communi-
cations ports
Section 9-4
Processing time and
fluctuation cause
0.3 ms
Same as for Normal Mode.
Same as for Normal Pro-
cessing Mode.
Same as for Normal Pro-
cessing Mode.
Processing time and
fluctuation cause
0.4 ms
1.0 ms for each type of
service
If servicing ends before
1 ms has expired, the
next type of servicing
will be started immedi-
ately without waiting.
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