Explain MIN instruction using example.

Explain MIN instruction using example.

Application:-Understand the concept of MIN instruction in the PLC. Write the PLC program using ladder diagram language to understand the concept.

 

Diagram:-

Explanation:-

Here we will understand the concept using an example. MIN instruction is used to define MIN value out of two values. So this instruction will compare two value and update the result in the output register.

For example assume we want to show MIN value out of two values. So we can take two values entry (MW10 and MW12 register for two value entry) in the HMI and one output field for output (the result will be updated in the MW14 register). In this entry field, we will enter two values here 50 and 60 so the output result will be 50.

PLC program:-

Write the ladder program for MIN instruction using ladder diagram language. Here for ladder logic, we can use any supported PLC system like S7-1200, S7-1500, or any other PLC which can support this instruction. In our application, we have used S7-1200 PLC for reference.

M Memory:-

IN 1:-MW40

IN 2:-MW42

OUT:-MW44

Network 1:- MIN instruction operation

PLC program Explanation:-

In network 1, we have taken MIN instruction. Here we are entering 50 in the MW 40 and 60 in the MW42 so the result will be updated in the MW 44 register. And it will be 50.

Explain NEG instruction in the PLC using an example.

Explain NEG instruction in the PLC using an example.

Application:-Understand the concept of NEG instruction in the PLC. Write the PLC program using ladder diagram language to understand the concept.

Diagram:-

Explanation:-

The negative instruction is used to invert the sign of the arithmetic value. It’s generally used to invert the sign of the value in the programming. So here we understand this instruction by example.

For explanation purpose, we can take the input register we can enter a value from the HMI and can see the result of this instruction. Take MW 10 register for input and link with HMI input I/O field and also take one output word address MW12 in the output field so we can monitor value in the display.

 

PLC program:-

Write the ladder program for NEG instruction using ladder diagram language. Here for ladder logic, we can use any supported PLC a system like S7-1200, S7-1500, or any other PLC which can support this instruction. In our application, we have used S7-1200 PLC for reference.

M Memory:-

Input value:-MW10

Output value:-MW12

Network 1:- NEG instruction operation

 

PLC program Explanation:-

In network 1, we have used NEG instruction. Here MW10 register is for input value and it is linked with the HMI input I/O field so if the user will enter value 10 in the HMI, it will be inverted into -10. This result will be stored in the MW 12 register so the user can monitor in the HMI. 

Explain 4:1 Multiplexer using an example.

Explain 4:1 Multiplexer using an example.

Application:-Make the 4:1 multiplexer. Write the PLC program for 4:1 multiplexer using ladder diagram language.

Diagram:-

Explanation:-

As shown in the above diagram we can see 4:1 multiplexer. S0 and S1 are the selection input for the multiplexer. So according to selection and input status output will be generated.

We can understand this concept simplified Boolean equation

Y = (S1=1 AND S0=1 AND I3=1) OR (S0=0 AND S1=1 AND I2=1) OR (S1=0AND S0=1 AND I1=1) OR (S0=0 AND S1=0 AND I1=1).

PLC program:-

Write the ladder program for 4:1 multiplexer instruction using ladder diagram language. Here for ladder logic, we can use any supported PLC system like S7-1200, S7-1500 or any other PLC which can support this instruction. In our application, we have used S7-1200 PLC for reference.

Digital Inputs:-

Selection switch 0:-I0.0

Selection switch 1:-I0.1

Input 1:-I1.1

Input 2:-I1.2

Input 3:-I1.3

Input 4:-I1.4

Digital Outputs:-

Output 1:-Q1.0

Network 1:- 4:1 Multiplexer ladder diagram PLC program Explanation:- In above network S1and S0 are the selection inputs. When S1 and S0 are high or 1 and I4 is 1, output Q1.0 will be high. When S0 is off and S1 is selected and I3 is on, output Q1.0 will be high. When S1 is off and S0 is selected and I2 is on, output Q1.0 will be high. When S0 is off and S1 is off and I1 is on, output Q1.0 will be high.