Motor ON OFF Logic in PLC

Develop ladder logic program for Motor ON OFF according to the logic given below,

The start button is pressed to start the conveyor motor
Cases move past the proximity switch and increment the counter’s accumulator value.
After the count of 3, the conveyor motor stops automatically and the counter’s accumulator value is reset to 0. Restart button is used to start the process from the beginning.
The conveyor motor can be stopped and started manually at any time without loss of the accumulator count.
Accumulated count of the counter can be reset manually at any time by means of the count reset button.

PLC Motor Logic

Motor Logic Explanation

Rung 0000:

Start/Stop PB latched with memory B3:0/0.

Rung 0001:

B3:0/0 enabled to turn ON conveyor motor (O:0/0 ). B3:0/1 is connected in series with normally closed contact to break the line when counter accumulator value reached 3.

Rung 0002:

B3:0/0 and proximity sensor (I:0/2) are connected in series to input the counter presented at 3 with one shot coil.

Rung 0003:

B3:0/0 and comparator block is used to enable B3:0/1 to turn OFF conveyor motor. It is also latched to avoid to restrict the motor to turn ON again. Restart button is pressed to start the process from the beginning.

Rung 0004:

Two ways are used to reset the counter, using manual reset switch and B3:0/1 when the counter accumulator reached preset value.

Program Output:

When Start PB is pressed

When three cases are passed

When the Restart button is pressed

Conclusion:

We can use this example to understand the programming logic in Allen Bradley Programmable Logic Controllers (PLC).

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...

Ferrules and Cross Ferruling

Ferrules are identification labels provided for every wire terminations in an instrument, equipment, or electrical/instrumentation control panels. These tube-shaped sleeves can be inserted easily on each individual wire in a multi-core cable. In earlier days fixed digits/letters are used as ferrules, but now Instrumentation engineers/technicians prints out desired ferrules by using a ferrule printing machine. Typical Ferrule The numbers/ letters on the ferrules will be given as per the approved electrical hook up or loop diagrams. This helps technicians to easily identify a particular loop/wiring from a series of terminal blocks and to troubleshoot the desired terminal connection. Separate numbers on the ferrules distinguish the positive and negative polarities of wires, thus ensure the polarity protection of the instrument. Cross Ferruling As a wire is connected on its both ends, it is quite useful to use a cross reference method for wire identification. Unlike normal ferru...

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...

TILI Automation

Search This Blog