Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual - Manual (Page 26)

Fundamentals of a
Programmable Controller
Chapter 2
2-12
The processor scans the program. Our program states that if (conditions)
input bit 02 is on, turn on output 02. If input bit 02 is off then output bit 02
is off. Since the alter condition is not true, the processor turns off output
bit 02.
When the processor next scans the output image table, it sees the zero in
output bit 02 and responds by de-energizing output terminal 02. The
action causes the conveyor to stop.