Omron SYSMAC CS1W-LCB01 Operation Manual page 76

Configuration of Instrumentation System
!Caution When using the Process-control CPU Unit (CS1D-CPU@@P), both the CPU
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b. Restrictions on Minimum Operation Cycle for Loop Controller In-
ternal Function Blocks
The operation cycle must be a minimum of 5 times the CPU Unit
cycle time.
When the Process-control CPU Unit (CS1D-CPU@@P) is used, it is
desirable to set the longest possible operation cycle to prevent errors
in the operation cycle. However, the operation cycle for the internal
function blocks of the Loop Controller component in the Process-con-
trol CPU Unit must be set to a minimum of 5 times the CPU Unit's nor-
mal cycle time. The normal cycle time is the cycle time other than
during duplex initialization.
Example: If the CPU Unit cycle time is 40 ms, the minimum operation
cycle for the function blocks in the Loop Controller component must be
at least 200 ms (i.e., 200 ms, 500 ms, 1 s, or 2 s.)
If the CPU Unit's normal cycle time is longer than 1/5 the minimum op-
eration cycle for the internal function blocks of the Loop Controller
component in the Process-control CPU Unit, the error in the operation
cycle will increase. The error can be an increase of up to one CPU Unit
cycle time.
Note If the CPU Unit's normal cycle time is longer than 30% of the mini-
mum operation cycle for the Loop Controller's internal function
blocks for 3 consecutive cycles, Auxiliary Area bit A42409 (Opera-
tion Cycle Error) will turn ON. Monitor this flag from the CX-Process
Tool system operation verification screen and if it turns ON, then
set the Loop Controller's operation cycle to a minimum of 5 times
the CPU Unit's normal cycle time.
c. Effect on the Cycle Time of the CPU Unit and the Operation Cycle
of the Process-control CPU Unit's Loop Controller during Duplex
Initialization
With the Process-control CPU Unit, a maximum of 152 seconds is re-
quired for duplex initialization. The CS1D CPU Units and the active
Loop Control Board will operate during duplex initialization. The CPU
Unit's cycle time and the Loop Controller's operation cycle, however,
will be temporarily longer than normal. This increase in the cycle time
and operation cycle will be the largest during the last cycle time during
which duplex initialization is being performed. The increase will be the
same for both the cycle time and the operation cycle.
Design the overall system so that no system errors will occur during an
extended cycle time and operation cycle. Refer to 3-5 Duplex Opera-
tion of Loop Controllers for details on duplex initialization.
d. Details of Extended CPU Unit Cycle Time and Extended Opera-
tion Cycle
• Duplex Initialization (Only in Duplex Mode)
Unit cycle time and the Loop Controller component operation cycle will be
temporarily longer than normal during Duplex Initialization (in Duplex Mode).
There will be a temporary extension to the cycle time and operation cycle of a
maximum of 2.1 s at a maximum of approximately 150 s after the start of
duplex initialization. The extended cycle time and operation cycle may tempo-
rarily worsen the control characteristics, so verify the system's operation in
trial operation before actually running the system.
Section 1-2