Programmed PUSH button to control ON/OFF of Output using PLC

Hi friends, In some application single push button is used for both ON/OFF.  For example in TV to Power ON/OFF  a single push button is used.  Sometimes because of lot of switches on the control panel there are greater chances to confuse ON or OFF switches, by using this type of switch we can save space and number of switches. Major advantages is that in PLC limited inputs are present, this type of switch can saves the no. of input terminals. For ON and OFF, two inputs is required but in this method we can achieve by using only one switch.

Ladder Diagram:

For above diagram Timer ON Delay contact is placed in first rung. As per ladder diagram POWER is the push button used to ON/OFF. If POWER switch is pressed less than 3sec OUT relay will latch, output will ON. If POWER switch is pressed more than 3sec OUT will resets. Because after 3sec timer will ON and contact of timer at 1^st rung will open and it breaks the connection of 1^st rung. Here in timer preset value is taken as 3sec, it can be changed by changing the value of Preset.

For simulation purpose use Siemens Logo Soft Comfort (Click Here To Download)and design ladder diagram which is given below

For the understanding purpose simple block/connection diagram is shown below. POWER button should be NO(Normally Open) type of PUSH button and input output rating voltage and current depends on the individual PLC. Therefore please refer PLC manual before connection.

Thank you all..

All the best…

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About Praveen S

Hello everyone, I am Praveen S, currently employed as "Technical Design Engineer" for Polycab Wires Pvt Ltd , I am a BE Graduate in EEE from NMAMIT Nitte (Karnataka, India). I am very passionate about learning and sharing my knowledge relating to the areas of "Electrical and Electronics". Here's my blog to share my ideas and to improve myself.