52
CPU Unit Operation
Section 2-4
2-4-2
I/O Refreshing and Peripheral Servicing
I/O Refreshing
I/O refreshing involves cyclically transferring data with external devices using
preset words in memory. I/O refreshing includes the following:
• Refreshing between I/O words in the CIO Area and CPU Unit built-in I/O,
CP-series Expansion Units, and CP-series Expansion I/O Units.
All I/O refreshing is performed in the same cycle (i.e., time slicing is not used).
I/O refreshing is always performed after program execution.
Peripheral Servicing
Peripheral servicing involves servicing non-scheduled events for external
devices. This includes both events from external devices and service requests
to external devices.
Most peripheral servicing involves FINS commands. The specific amount of
time set in the system is allocated to each type of servicing and executed
every cycle. If all servicing cannot be completed within the allocated time, the
remaining servicing is performed the next cycle.
Note
(1) Ethernet port, serial port, and communications port servicing is allocated
8% of the previous cycle time by default (the default can be changed) for
each service. If servicing is separated over many cycles, delaying com-
pletion of the servicing, set the same allocated time (same time for all ser-
vices) rather than a percentage under execute time settings in the PLC
Setup.
(2) An error will be occurred if the cycle time is too long. Modify the CX-Pro-
grammer’s response monitoring time longer according to the following
method.
Start the CX-Programmer. Select Change Model from the
PLC
Menu.
The
Change PLC
Dialog Box will be displayed. Click the
Settings
Button
on the right side of
Network Type
. The
Network Settings [USB]
Dialog
Box will be displayed. Click the
Network
Tab and increase the value in
Response Timeout(s)
.
Units
Max. data exchange
Data exchange area
CPU Unit built-in I/O
2 input words
2 output words
I/O Bit Area
CP-series Expansion Units
and Expansion I/O Units
Fixed depending on Units I/O Bit Area
Service
Description
Ethernet port servicing
• Non-scheduled servicing for communications
(either sending or receiving) via the Ethernet port.
Serial port servicing
• Non-scheduled servicing for FINS or Host Link
commands received via a serial port from the CX-
Programmer, PTs, or host computers (e.g.,
requests for program transfers, monitoring, forced-
set/reset operations, or online editing)
• Non-scheduled servicing from the CPU Unit trans-
mitted from a serial port (non-solicited communica-
tions)
Communications port servic-
ing
• Servicing to execute network communications or
serial communications for the SEND, RECV, CMND
instructions using communications ports 0 to 7
(internal logical ports)
• Servicing to execute background execution using
communications ports 0 to 7 (internal logical ports)
Built-in flash memory access
servicing
• Read/write processing for built-in flash memory
Memory Cassette access ser-
vicing
• Read/write processing for a Memory Cassette
Содержание CP1L-EL20DR-D
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Страница 34: ...xxxiv Software Licenses and Copyrights 7...
Страница 178: ...144 Connecting the CX Programmer Section 5 1 Click the Connect button to connect and then connection online is completed...
Страница 192: ...158 Trial Operation and Debugging Section 5 3...
Страница 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Страница 666: ...632 Trouble Shooting Section 11 7...
Страница 696: ...662 Standard Models Appendix A...
Страница 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Страница 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Страница 836: ...802 PLC Setup Appendix G...
Страница 838: ...804 TCP Status Transitions Appendix H...
Страница 840: ...806 Ethernet Network Parameters Appendix I...
Страница 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Страница 844: ...810 Ethernet Specifications Appendix K...
Страница 851: ...Index 817 work words 118 write protection 447...
Страница 852: ...818 Index...
Страница 854: ...820 Revision History...
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