Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 681

Data Control Instructions
Note
Execution
Input Read Timing Setting
(C bits 08 to 11)
648
When the output limit control function is enabled, set the lower and upper lim-
its as follows: 0000 hex
• The instruction is executed while the input condition is ON.
• When instruction execution starts, the output bit (R) is turned ON/OFF
according to the duty ratio.
• The parameters (in C to C+3) are read in real time each time that the
instruction is executed. When changing the parameters, change all of
them at the same time so that different sets of parameters are not mixed.
• 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 duty ratio will be read in real time each time the
lower limit upper limit
Description
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.
instruction is executed and the ON/OFF operation will be
repeated within the control period.
Section 3-17
2710 hex.