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2-2 cycle time overview, 4 monitoring and computing the cycle time – Omron SYSMAC CP CP1E-N@@D@-@ User Manual

Page 452

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4 Monitoring and Computing the Cycle Time

4-4

CP1E CPU Unit Instructions Reference Manual(W483)

The cycle time depends on the following conditions.

Type and number of instructions in the user program (cyclic tasks and all interrupt tasks for which the

execution conditions have been satisfied)

Type and number of CP-series Expansion Units and Expansion I/O Units

Minimum (constant) cycle time setting in the PLC Setup

Use of peripheral USB and serial ports

Precautions for Correct Use

Precautions for Correct Use

When the mode is switched from MONITOR mode to RUN mode, the cycle time may be extended
by 10 ms (this will not, however, cause a cycle time exceeded error).

The cycle time is the total time required for the PLC to perform the operations given in the following
tables.

Cycle time = (1) + (2) + (3) + (4) + (5)

(1) Overseeing

(2) Program Execution

(3) Cycle Time Calculation for Minimum Cycle Time

(4) I/O Refreshing

4-2-2

Cycle Time Overview

Operation

Processing time and

fluctuation cause

Checks the I/O bus and user memory, checks for battery errors,
etc.

0.4 ms min.

Operation

Processing time and

fluctuation cause

Executes the instructions in the user program. The time
required is the total of the executions times for all instructions.

Total instruction execution
time.

Operation

Processing time and fluctuation cause

Waits for the specified cycle
time to elapse when a minimum
(constant) cycle time has been
set in the PLC Setup.

Calculates the cycle time.

When a minimum cycle time is not set, the time for step 3 is
approximately 0.

When a minimum cycle time is set, the time for step 3 is the
preset fixed cycle time minus the actual cycle time
((1) + (2) + (4) + (5)).

Operation

Processing time

and fluctuation

cause

CPU Unit built-in I/O, CPU
Unit built-in analog I/O (NA-
type only), CP-series Expan-
sion Units and Expansion I/O
Units

Outputs from the CPU Unit to the
actual outputs are refreshed first for
each Unit, and then inputs.

I/O refresh time for
each Unit multiplied
by the number of
Units used.

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