Basic PLC Ladder Programming Examples 7

Basic PLC
Ladder Programming Training Examples for Beginners.

friends here we are starting here a series of Free Training on PLC
Ladder Programming training & tutorials.These PLC Ladder Programs
are important to get basics of Ladder programs.

Practice Problem: 

Enabling the indicator to be ON after a 3 sec delay when switch pressed and
OFF immediately by the switch


 Topics Covered in this example is PLC Timer (ON Delay).

Number of PLC Inputs Required

X1 – Start Switch.

Number of PLC Outputs Required

Y1 – Output Indicator

Number of PLC Timer Required

T0 – 3 second Timer, 100 ms Time Base. (See K30 Preset Value for Timer)

PLC Ladder Programming:

PLC Ladder Program Description:

When X1 = ON, TMR instruction will be executed. Timer T1 will be ON and
start counting for 3 sec. When T1 reaches its set value, the NO (Normally Open)
contact T1 will be activated and indicator YI will be ON. 
When X1 = OFF, TMR instruction will not be executed. Timer T1 will be
OFF and so will NO contact T1. Therefore, the indicator Y1 will be OFF. 


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