Omron SYSMAC C Series User Manual page 56

Application examples
Ladder diagram
0003
Instruction
LD-NOT
Explanation
If a defective product (a bottle without a label) is detected, the C20
directs a robot arm to remove the bottle and place it on another conveyor
line. The C20 also counts the number of defective products. If their
number reaches a preset value, the C20 causes an alarm lamp to go on.
1/0 assignment
Label missing detection
Bottle detection
Stop soe - 3
Robot arm's original position detection
Output
Robot arm
Conveyor B motor
Alarm lamp
Operation
This application makes use of the shift register (SFT) instruction. This
instruction must be programmed in the order of data input (0000), clock
input (0001), and reset input (0002). Moreover, the instruction data must
be specified in channel units.
In this example, channel 10 is specified as the data. When a defective
product (a bottle bearing no label) is detected, input 0000 is turned on
and the state is stored in point 1000 of channel 10. At the next input signal
of 0001, the state of point 1000 of channel 10 is shifted to 1001, indicating
detection of a defective product. In response, output 0500 is issued
unless input 0003 is applied. When output 0500 is issued, the robot
arm removes the defective product on conveyor A and places it on
conveyor B.
Input 0003 is turned on when the arm of the robot, after removing the
defective bottle, returns to its original position. When relay 1001 is turned
on, output 0501 is also issued, starting conveyor B.
Inputs 0000 and 0002 also serve as the count input and reset input,
respectively, of the counter. When the counter counts five count inputs
(five defective bottles), the counter turns on output 0502, which in turn
illuminates the alarm lamp.