Omron CJ - REFERENCE MANUAL 02-2010 Reference Manual page 702

3. Instructions
• The output (R) is turned ON/OFF when the instruction is executed and the accuracy of the output's
ON/OFF timing is 10 ms max.
• Execution of the instruction stops when the input condition goes OFF. At that time, the elapsed time
value will be reset and the control period will be initialized.
• The input type setting (bits 04 to 07 of C) determines whether the input word (S) contains a duty ratio
or manipulated variable. When S contains the manipulated variable, the duty ratio is calculated by
dividing the manipulated variable input by the manipulated variable range (bits 00 to 03 of C).
• The input read timing setting (bits 08 to 11 of C) specifies when the input word (S) is read, as shown
in the following table:
Input read timing
0: Use the beginning value
of the control period
1: Use lower value
2: Use higher value
3: Continuous adjustment
The following diagrams show the operation of each input read timing setting.
• Input time setting = 0 (Use the beginning value of the control period.)
Read only at the beginning of the control period.
Duty ratio
(MV/MV range)
• Input time setting = 1 (Use lower value.)
Duty ratio
(MV/MV range)
666
The duty ratio input is read at the beginning of the control period and the ratio cannot be
changed during the control period.
If the duty ratio input falls below the duty ratio at the beginning of the control period, the lower
value will take precedence and the output ON time will be reduced accordingly.
If the duty ratio input rises above the duty ratio at the beginning of the control period, the
higher value will take precedence and the output ON time will be increased accordingly.
The duty ratio will be read in real time each time the instruction is executed and the ON/OFF
operation will be repeated within the control period.
Control period (a)
100%
70%
55%
0%
a 0.55 s
Output
Each control period's output is determined by the duty ratio at the beginning of that period.
Use this setting for general applications.
Control period (a)
100%
70%
55%
35%
0%
a 0.35 s
Output
If the duty ratio falls below the initial value early enough, the duty ratio will be
adjusted and the output will be turned OFF sooner.
Use this setting for applications such as avoiding overshooting when using
time-proportional control to control heating and using a relatively long control period.
Description
Control period (a)
a 0.45 s a 0.70 s
Control period (a)
55% target
70% target
cut to 35%.
is kept.
a 0.70 s
a 0.65 s
CS/CJ/NSJ Series Instructions Reference Manual (W474)
a 0.30 s
Time
a 0.30 s
Time