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Exercise: Energy Saving Escalator
This section explains the operation of the TON instruction.
This escalator does not move until someone approaches it. When a person passes in front of
the sensor (SW1), the motor (L1) starts. In order to save energy, the motor stops in five
seconds after the last person passes.
Tips
(1) Modify the created program.
(2) Insert an N.C. Input for timer output in the rung to stop the motor. There are two N.C.
input methods
① Specify timer output as a work bit (e.g., Timer1UP).
② Use Timer1.Q that represents the output status of the timer instruction.
(3) Modify so as to reset the timer when a person passes.
Add an N.C. Input (Timer1UP) in the first rung to stop L1 (the motor of the escalator in this
example) when Timer1UP changes to TRUE. Add another N.C. Input (SW1) to reset the
present value of the TON instruction. The program is completed.
■ Example (Output Timer1UP for when Timer1 times out)
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