Chapter 2 Devices A. The general-purpose timer When the instruction TMR is executed, the general-purpose timer begins to count. As the value of the timer matches the setting value, the output coil is ON. When X0.0 is ON, the timer T0 takes 100 milliseconds as the timing unit and counts up. As the current value of the timer matches the setting value 100, the output coil of T0 is ON. When X0.0 is OFF or there is a power cut, the current value of the timer is reset to 0 and the output coil is switched OFF. B. The accumulative timer When the instruction TMR is executed, the accumulative timer begins to count. As the value of the timer matches the setting value, the output coil is ON.
As long as users add the letter S in front of the letter T, the timer becomes the accumulative timer. When the conditional contact is OFF, the value of the accumulative timer is not reset. When the conditional contact is ON, the timer counts from the current value. When X0.0 is ON, the timer T250 takes 100 milliseconds as the timing unit and counts up. As the current value of the timer matches the setting value 100, the output coil of T250 is ON. When X0.0 is OFF or there is a power cut, the timer T250 stops counting and the current value of the timer remains unchanged. Not until X0.0 is switched ON will the timer counts again.
When the timer counts up from the current value to the setting value 100, the output coil of T250 is ON. 2-45