Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 367

CPU Unit Operation
Parallel Processing (Single CPU Systems Only)
1,2,3...
Power ON
Startup
initialization
Initialize hardware
memory and system
work area.
Detect I/O.
Automatically transfer
data from Memory
Program
Card.
Execution
Cycle
Overseeing
processing
Program
execution
I/O
refreshing
Program
(even in
execution
PROGRAM
cycle time
mode)
Perform the following servicing if any events
Peripheral
have occurred.
servicing
File access servicing
Note: In Parallel Processing with Synchronous
Memory Access, any events requiring I/O
memory access are serviced here.
The following two types of processing are performed in parallel in either of the
Parallel Processing Modes.
1. Program execution: Includes user program execution and I/O refreshing. It
is this cycle time that is monitored from a Programming Device.
2. Peripheral servicing: Programming Devices and events from Special I/O
Units and CPU Bus Units are serviced when they occur.
There are two different Parallel Processing Modes. Parallel Processing with
Synchronous Memory Access refreshes I/O memory in the program execution
cycle and Parallel Processing with Asynchronous Memory Access refreshes
I/O memory in the peripheral servicing cycle.
Verify actual Units with
registered I/O tables.
Clear I/O memory.
Check user memory.
Clear forced status,
etc.
Read DIP switch settings.
Check I/O bus.
Operation processing: Execute the user
program.
Error processing: Turn OFF outputs.
(Reset Units for bus errors.)
After error: Clear I/O memory is an error
occurs (unless a FALS(007) instruction
created the error).
Refresh data for the following Units.
Basic I/O Units
SYSMAC BUS Remote I/O Master Units
Special I/O Units (both words allocated in
CIO and DM area and specific data for
each Unit)
CPU Bus Units (both words allocated in
CIO and DM area and specific data for
each Unit)
Inner Boards (both words allocated in CIO
and DM area and specific data for each
Unit)
Note Always disconnect the Programming Console from the peripheral port during
actual system operation in a Parallel Processing Mode. If the Programming
Console is left attached, excess time will be allocated to increase key
response for the Programming Console, adversely affecting performance.
Peripheral Servicing Cycle
Overseeing
processing
Peripheral Peripheral
servicing
servicing
cycle time
Section 9-1
Check the Battery.
Check I/O bus.
Check user program
memory.
Perform the following servicing if any
events have occurred.
Special I/O Unit event servicing
CPU Bus Unit event servicing
Peripheral port servicing
RS-232C port servicing
Inner Board event servicing
Communications port servicing
Note: In Parallel Processing with
Synchronous Memory Access, any
events requiring I/O memory access are
serviced in the program execution cycle.
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