Explain equal instruction using example

Explain equal instruction using example

Application:-Explain Equal instruction in the PLC. Write PLC program for explanation using ladder diagram language.

Components:-Programmable logic controller, HMI panel, wires, 24 VDC lamp, 24 VDC power source.

Diagram:-

Explanation:-

Consider a simple example for explanation of equal instruction in the PLC. Here we have taken simple HMI (Human Machine Interface) for display and programmable Logic Controller (PLC) for programming. Take two value set value 1 and set value 2 for example. Here if both the value in the set value 1 and set value 2 equal then lamp will be ON. So we need to use == instruction for above example.

Enter 50 value in the set value 1 box and enter 50 value in the set value 2 box so lamp should be ON and if someone enter 25 value in the set value 2 box, lamp should not be ON.

PLC program:-

Write the ladder program for above application using ladder diagram language. Here for ladder logic we can use any supported PLC system like S7-1200, S7-300, S7-1500 or any other PLC which can support this instruction. For PLC logic we need digital inputs and outputs.

For our application lamp is digital output. Two set values from the HMI are input words.

Digital Output:-

Lamp=Q0.0

M Memory:-

Set value 1:-MW10

Set Value 2:-MW12

PLC program Explanation:-

In network 1 we tow values are compared with comparison instruction. Set value 1 (MW) is compared with Value 2 (MW12).Hence if both values are equal, lamp (Q0.0) will be ON.

In comparator instruction, two operands are compared, we can set data time in comparator instruction.