3 . Timer Design Examples Control Program: Y0 X0 X2 Y1 Y0 X2 X0 T0 X0 X1 Y0 Y1 Y1 Program Description: z X0 = ON if someone enters the sensing field of the infrared sensor. Y0 will be ON and latched, and the door will be opened as long as the opening limit switches X2 = OFF. z When the door touches the opening limit switches, X2 = ON. The timer T0 will start to count for 7 sec if no one enters the sensing field (X0 = OFF). After 7 sec., Y1 will be ON and latched and the door will be closed. z During the closing process, X0 = ON if someone enters the sensing field. The NC contact X0 will be activated to turn Y1 off.
Because X0 = ON, X2 = OFF and Y1 = OFF, Y0 will be ON and the door will be opened once again. DVP-PLC Application Examples 3-14 TMR T0 K70