Determining The System Configuration - Omron CS1W-LC001 Operation Manual

Configuration of Instrumentation System
1-2-2

Determining the System Configuration

1, 2, 3...
Check the following points when determining the system configuration:
1. Number of Analog I/O Points Used on Loop Control Unit
Which analog signals are input/output on the AI/AO terminals of the Field
Terminal block, and which analog signals are input/output on the CPU
Unit Terminal block or the Expanded CPU Unit Terminal block?
The total number of usable AI/AO terminals on the Field Terminal block
combined with the DO/DI terminals is 80. (For details of the unit types
that can be used, see page 30.)
The maximum number of usable CPU Unit Terminal blocks is 16. (For
details of I/O memory area that can be specified, see page 31.)
2. Number of Contact I/O Points Used on Loop Control Unit
Which contact signals are input/output on the DI/DO terminals of the
Field Terminal block, and which contact signals are input/output on the
CPU Unit Terminal block or the Expanded CPU Unit Terminal block?
The total number of DI/DO terminals on the Field Terminal block
combined with the AO/AI terminals is 80. (For details of the unit types
that can be used, see page 33.)
The maximum number of usable CPU Unit Terminal blocks is 16. (For
details of I/O memory area that can be specified, see page 33.)
3. Current Consumption
Is the current consumption of the units mounted on the rack less than the
current consumption of the Power Supply Unit?
Refer to CS1-series Operation Manual (Catalog No. W339-E1), 2-6 Unit
Current Consumption.
4. Evaluation of Load Rate
The Loop Control Unit cyclically processes operation of its own function
blocks asynchronously with I/O refreshing of the CPU Unit. The cycle by
which operations are processed, or the "operation cycle," is dependent
on the type and number of function blocks used.
For this reason, when many function blocks whose operation takes a long
time to process are used, the actual operation cycle of the entire Loop
Control Unit or an individual function block increases. As a result, the
desired preset operation cycle sometimes cannot be satisfied.
The ratio between the actual execution time required for processing
operation and the preset operation cycle is called the "load rate." The
maximum values and current value of each operation cycle group can be
confirmed on CX-Process Tool.
A load rate of 60% or less is required in all operation cycle groups on this
Loop Control Unit.
Section 1-2
27