In the example above, when the operator pushes button 0002 the timer starts ticking. When the accumulated value reaches 0 the timer contacts (T000) will close and output 0500 becomes true. When the operator releases the button (0002) the accumulated value is held(i.e. retained). Only when the operator pushes the reset button(0001) does the timer reset.Press your browsers BACK button or click here to return to the PLC Tutor.