Skip to main content

One Shot Rising and One Shot Falling Instructions in PLC

 To study the working of One Shot Rising (OSR) and One Shot Falling (OSF) functions in Allen Bradley programmable logic controllers (PLC).

One Shot Rising and One Shot Falling Instructions

In the above instruction block of One shot Rising (OSR) or One shot falling (OSF),

There are two Variables,

Storage Bit: This bit is to store the status of input.

Output Bit: This bit store the value when it executes the function of Block

One Shot Rising (OSR)
One shot rising is similar to ONS except the storage and output bits. It gives single pulse at the time of going ON condition. Storage bit stores the status of input.

Output bit stores the status of function performed by the block.

One Shot Falling (OSF)
One shot falling gives single pulse at the time of going input’s OFF condition  which is connected to it. Storage bit stores the status of input. Output bit stores the status of function performed by the block.

PLC Program using OSR and OSF
Ladder Logic Explanation
RUNG 0000
Input 1 (I:0/0) is connected to OSR block. When input is turned ON, Storage bit (B3:0/0) turns 1 and output bit (B3:0/1) turns “1” for a second and goes to “0” again.

RUNG 0001

Input 2 (I:0/1) is connected to OSF block. When input is turned ON, Storage bit (B3:0/2) turns 1 and output bit (B3:0/3) remains “0”.When Input turns OFF, Output bit turns “1” for a second and goes to “0” along with storage bit.
Conclusion
We can use this example program to understand the working of one shot rising (OSR) and one shot falling (OSF) function in Allen Bradley programmable logic controllers (PLC).


Comments

Popular posts from this blog

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...