Omron SYSMAC CS1W-LCB01 Operation Manual page 75

Configuration of Instrumentation System
Note The High Load Alarm Flag (A42408) turns ON if the load rate exceeds 80%
for 6 seconds. If this happens, select the function blocks that can have longer
operation cycles and increase their operation cycles. If the load rate is still too
high, add on a CPU Unit or a CPU Unit and a Loop Control Unit and distribute
function block processing between the mounted Units.
5. CPU Unit Cycle Time and Minimum Operation Cycle (Process-control
CPU Unit Only)
When the Process-control CPU Unit (CS1D-CPU@@P) is used, the CPU
Unit cycle time must be considered in relation to the minimum operation
cycle in relation to the load rates outlined above.
a. Effect on CPU Unit Cycle Time
Effect on Normal CPU Unit Cycle Time
The following table shows the extra time added to the normal CPU Unit
cycle time when a Loop Controller is mounted.
Functional
component
Loop Control Board
(CS1W-LCB01/05)
Loop Controller com-
ponent in the Pro-
cess-control CPU
Unit (LCB05D)
Example of the Influence of the Process-control CPU Unit's Loop
Controller on Normal Cycle Time
Function block and user link table opera-
tion cycle (See note (a).)
Number of function blocks
Number of user link tables
Load rate
Influence (ms) by 2-ms cycle time of ladder
program (See note (b).)
Influence (ms) by19-ms cycle time of lad-
der program (See note (b).)
Note (a) The influence of the function block and user link table operation
cycle on the CPU Unit's cycle time is greatest when the function
block and user link table operation cycle is 100 ms.
(b) The influence of the CS1D-LCB05D on the CPU Unit's cycle time
is greatest when the cycle time of the CPU Unit is 19 ms.
(c) When sequence tables are used, the extra time in the above table
is further extended. The additional extra time required depends
on how the sequence tables are used, as follows:
• Not expanding sequence tables: +3 ms
• Expanding sequence tables vertically or horizontally: +6 ms
• Expanding sequence tables both vertically and horizontally:
+12 ms
The extended cycle time will not be lengthened if the number of ex-
panded sequence tables increases, but the number of times that
the cycle time is extended will increase.
Extra time added to normal cycle time
0.8 ms (depending on the function block data con-
tents)
25 ms max. (depending on the function block data
contents)
100 ms
100
100
39
+7.8
+10.3
Section 1-2
150 200
150 200
55 71
+10.5 +13.6
+14.4 +20.8
41