A
A-3 Inner Workings of CP1L
SYSMAC CP1L Getting Started Guide 111
Appendix
Cycle Time
CPU units process data in cycles starting with Overseeing processes and ending
with Peripheral services.
zCalculating Cycle Time
The cycle time is calculated as the sum of the following processing times.
Cycle Time = Overseeing Processes + Program Execution + (Cycle Time
Calculation) + I/O Refresh + Peripheral Services
Overseeing Processes
Program execution
For details, refer to SECTION 4 Instruction Execution Times and Number of Steps
of CP Series CP1H/CP1L CPU Unit Programming Manual (W451).
Cycle Time Calculation
I/O Refreshing
For details on I/O refresh time, refer to 2-7 Computing the Cycle Time of CP Series
CP1L CPU Unit User’s Manual (W462).
Details Processing Time and
Variation Factors
Checks I/O buses.
Checking of user program memory, battery error, etc.
0.4ms
Details Processing Time and
Variation Factors
Processes program execution (execution of instructions). The
processing time is the sum of individual instruction execution
times.
Sum of instruction
execution times
Details Processing Time and Variation Factors
Waits for the specified cycle time to
elapse when a minimum (fixed) cycle
time is specified in PLC Settings.
Calculates the cycle time.
When the cycle time has not been fixed, the
processing time is approximately 0.
Additional time for fixing the cycle time =
Fixed cycle time – Actual cycle time
(processing time for: overseeing processes +
program execution + I/O refreshing + peripheral
services)
Details Processing Time and
Variation Factors
CP-series Expansion I/O Units and
Expansion Units
Each unit is refreshed.
Outputs (from the CPU unit
to the expansion units) are
refreshed first, followed by
the inputs (from the
expansion units to the CPU
unit).
I/O refresh time for
each unit is multiplied
by the number of
units used
W07E-EN-02+CP1L+GettingStartedGuide.book Seite 111 Montag, 15. September 2008 11:15 11
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