Omron SYSMAC CS Series User Manual

130
Description of Operation Section 3-2
Note Set by User Link Tables for the Process-control CPU Unit (CS1D-
CPU@@P). The replacement processing is refreshed over multiple
cycle times within the operation cycle.
3-2-17 About the LCB Load Rate
The minimum operation cycle of each of the function blocks on the Loop Con-
troller can be set to 0.1 seconds. However, when many function blocks are
used, the processing capability of the Loop Controller prevents processing at
the specified operation cycle. For this reason, the Loop Controller is provided
with the LCB load rate concept as an indicator of its processing capability.
This load rate is one condition for determining the operation cycle of the func-
tion blocks. (See 3-2-15 Conditions for Determining the Operation Cycle.)
The LCB load rate is a fixed load rate plus the summation of all actual execu-
tion times (the time required for execution before idling) divided by the corre-
sponding set operation times.
The actual operation execution cycle is a total of the following two times:
1,2,3... 1. Overhead time (FINS command communications and internal processing)
2. Total operation execution time of each function block in the same operation
cycle group
3-2-18 Evaluating the LCB Load Rate at the System Design Stage
The guideline LCB load rate for function blocks on the Loop Controller is 80%.
At the system design stage study whether or not the LCB load rate of each
function block is 80% or less.
Block A
Block F
Block A
Block F
Time
Actual operation time
Set operation cycle: 2 s
Idling
Actual operation time
Set operation cycle: 2 s
Idling
Block G
Actual
operation
time
Set operation cycle: 1 s
Idling
Block G
Actual
operation
time
Set operation cycle: 1 s
Idling
Block G
Actual
operation
time
Set operation cycle: 1 s
Idling
Block G
Actual
operation
time
Set operation cycle: 1 s
Idling
Block
X
Block
X
Actual
operation
time
Idling
Set operation cycle: 10 ms
Tim
e
Time
LCB load rate is the time actually required for actual operation for all operation cycles divided by the summation
of the set operation cycles plus a fixed load rate.
+)
LCB load rate =
Σ
Actual operation time
Set operation cycle
+ Fixed load rate

Omron SYSMAC CS Series Specifications

General

Brand	Omron
Model	SYSMAC CS Series
Category	Controller
Language	English