Omron CP1H CPU UNITS - PROGRAMMING 05-2007, Operation Manual

Page: 117 / 788

83
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 CPU Unit built-in I/O, CP-series Expansion Units,
and CP-series Expansion I/O Units and I/O words in the CIO Area
• Refreshing between CJ-series Special I/O Units and CJ-series CPU Bus
Units and the words allocated to these in the CIO Area (and for CPU Bus
Units, words allocated in the DM Area)
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.
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
CJ-series Spe-
cial I/O Units Words allocated in CIO Area 10 words/Unit (Depends
on the Unit.) Special I/O Unit Area
Unit- specific
data CompoBus/S
Master Unit Depends on the Unit. Remote I/O Communications Area
CJ-series CPU
Bus Units Words allocated in CIO Area 25 words/Unit CPU Bus Unit Area in CIO Area
Words allocated in DM Area 100 words/Unit CPU Bus Unit Area in DM Area
Unit-specific
data Controller Link
Unit Depends on the Unit. Words set for data links (for either fixed
or user-set allocations)
DeviceNet Unit Depends on the Unit. Words set for remote I/O communica-
tions (for either fixed or user-set alloca-
tions)
Serial Commu-
nications Unit Depends on the protocol
macros. Communications data set for protocol
macros
Ethernet Unit Depends on the Unit. Communications data for socket ser-
vices initiated by specific control bit
operations.
Service Description
Event servicing for CJ-series
Special I/O Units • Non-scheduled servicing for FINS commands from
CJ-series Special I/O Units and CJ-series CPU Bus
Units
• Non-scheduled servicing for FINS commands from
the CPU Unit to the above Units.
Event servicing for CJ-series
CPU Bus Units
USB port servicing • Non-scheduled servicing for FINS or Host Link
commands received via a USB port or 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