Motor Stop Interlock for Changing the Direction PLC Program

Write a PLC program where you can’t change the motor direction unless the stop push button is pressed first.

For instance, If the clockwise (CW) push button (PB) is pressed the motor runs in CW and if the counter-clockwise (CCW) push button is pressed the motor does not change its direction unless the stop push button is pressed first.

Note: the best practice to learn the PLC programming is to start writing the PLC program, take your time before you review the answer.

Inputs and Outputs:

I0.0: CW Push Button (Normally Open contact)

I0.1: CCW Push Button (Normally Open Contact)

I0.2: Stop Push Button (Normally Closed contact)

Q0.0: Motor CW

Q0.1: Motor CCW

Motor Stop Interlock for Changing the Direction

PLC Program description

Network 1:

When the CW PB is pressed and the Motor CCW is not running the set bit in the flip flop is energized.

When the stop PB is pressed the reset bit in the flip flop is energized.

If the CW PB is pressed while the Motor CCW is running the set bit would never be energized

Network 2:

When the CCW PB is pressed and the Motor CW is not running the set bit in the flip flop is energized.

When the stop PB is pressed the reset bit in the flip flop is energized.

If the CCW PB is pressed while the Motor CW is running the set bit would never be energized.

Conclusion

There is an interlock between the two motor directions that it is not allowed to toggle between the two directions unless the motor is stopped.

Comments

PLC Program for Mixing Tank

Create a ladder diagram for controlling a batch mixing process. Implement a PLC program for mixing tank or Mixing Process using PLC Ladder Logic. PLC Program for Mixing Tank Fig : Mixing tank A tank is used to mix two liquids. The required control circuit operates as follows: A. When the START button is pressed, solenoids A and B energize. This permits the two liquids to begin ﬁlling the tank. B. When the tank is ﬁlled, the ﬂoat switch trips. This de-energizes solenoids A and B and starts the motor used to mix the liquids together. C. The motor is permitted to run for 1 minute. After 1 minute has elapsed, the motor turns off and solenoid C energizes to drain the tank. D. When the tank is empty, the ﬂoat switch de- energizes solenoid C. E. A STOP button can be used to stop the process at any point. F. If the motor becomes overloaded, the action of the entire circuit will stop. G. Once the circuit has been energized, it will continue to operate until it is manually stopped. Solution...

What is Relay? How it Works? Types, Applications, Testing

We use relays for a wide range of applications such as home automation, cars and bikes (automobiles), industrial applications, DIY Projects, test and measurement equipment, and many more. But what is Relay? How a Relay Works? What are the Applications of Relays? Let us explore more about relays in this guide. What is a Relay? A Relay is a simple electromechanical switch. While we use normal switches to close or open a circuit manually, a Relay is also a switch that connects or disconnects two circuits. But instead of a manual operation, a relay uses an electrical signal to control an electromagnet, which in turn connects or disconnects another circuit. Relays can be of different types like electromechanical, solid state. Electromechanical relays are frequently used. Let us see the internal parts of this relay before knowing about it working. Although many different types of relay were present, their working is same. Every electromechanical relay consists of an consists of an Elect...

Chlorine dioxide Analyzer Principle

Chlorine dioxide measurement Chlorine dioxide (ClO2) is an instable, non-storable, toxic gas with a characteristic scent. The molecule consists of one chlorine atom and two oxygen atoms – represented in the chemical formula ClO2. It is very reactive. To avoid the risk of spontaneous explosions of gaseous chlorine dioxide or concentrated solutions, it is generally handled in dilution with low concentrations. ClO2 is soluble in water, but tends to evaporate quickly. Typically it is prepared on site, for example from hydrochloric acid and sodium chlorite. The procedure provides solutions with approx. 2 g/l ClO2 that can be safely handled and stored for several days. Image Credits : krohne Sensor Parts : Reference electrode Applied chlorine dioxide specific potential Current needed to maintain the constant potential Counter electrode Measuring electrode The disinfection effect of ClO2 is due to the transfer of oxygen instead of chlorine, so that no chlorinated byproducts are formed. C...

TILI Automation

Search This Blog