What is meant by interlocking in PLC programming?

An interlock is a feature that makes the state of two mechanisms or functions mutually dependent. It may be used to prevent undesired states in a finite-state machine, and may consist of any electrical, electronic, or mechanical devices or systems.

How do traffic lights operate through PLC?

The PLC checks the status of the sensors. The system resolution is dependent on the output provided by the sensors, then PLC checks the priorities and then provide output signal to the traffic light poles for ON or OFF the red, yellow or green lights and ON time is dependent on the specific priorities.

How do you program a light sequence?

PLC Programming to Control Lights in a Sequence

1. Three lights (L1, L2, L3) 3 sec apart.
2. Turn Off all the lights after 6 sec.
3. Three lights (L1, L2, L3) 2 sec apart.
4. Turn Off all the lights after 4 sec.
5. Three lights (L1, L2, L3) 1 sec apart.
6. Turn Off all the lights after 2 sec.
7. Repeat the sequence from step 1.

What is the use of interlocks on drives?

Alcohol interlocks are automatic control systems which are designed to prevent driving with excess alcohol by requiring the driver to blow into an in-car breathalyser before starting the ignition. The alcohol interlock can be set at different levels and limits.

What is the function of interlock?

An interlock is a type of device that is used to prevent undesirable conditions in machines, which may include mechanical or electronic systems or devices. In almost all applications, it is utilized to aid in preventing machines from causing harm to the machine itself or to the operators.

What is a rung on a ladder logic diagram?

Horizontal lines in a ladder diagram are called “rungs,” each one representing a unique parallel circuit branch between the poles of the power supply.

What are safety interlocks?

Safety interlock switches are used as interlock devices that can prevent machine operation or startup in an unsafe situation, such as when a door or guard is open. Interlock devices with a locking function can also prevent doors or guards from being opened while the machine is in operation.