I/O Refresh Methods - Omron CP1H-CPU - 05-2006 Operation Manual

Cp1h cpu unit

Table of Contents

CPU Unit Operation

I/O Refresh Methods

Cyclic Refreshing

Communications port servic-

Built-in flash memory access

Memory Cassette access ser-

CJ-series Special I/O Unit, CJ-series CPU Bus Unit, USB port, serial port,

and communications port servicing is allocated 4% of the previous cycle time

by default (the default can be changed) for each service. If servicing is sepa-

rated over many cycles, delaying completion of the servicing, set the same

allocated time (same time for all services) rather than a percentage under

execute time settings in the PLC Setup.

I/O for CPU Unit built-in I/O and I/O on CPM1A Expansion Units and Expan-

sion I/O Units is performed at the following times.

1. Cyclic refresh period

2. When instructions with an immediate refresh variation are executed

3. When IORF(097) is executed

I/O is refreshed after all the instructions in executable tasks have been exe-

I/O refresh period

• Servicing to execute network communications or

serial communications for the SEND, RECV, CMND

or PMCR instructions using communications ports

0 to 7 (internal logical ports)

• Servicing to execute background execution using

communications ports 0 to 7 (internal logical ports)

• Read/write processing for built-in flash memory

• Read/write processing for a Memory Cassette

I/O terminal

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