Getting Started with DIN Simul8

In this tutorial you'll be guided in connecting the Arduino® DIN Simul8 to the Arduino Opta® WiFi, and trigger some basic functions.

Hardware & Software Requirements

Hardware

• Arduino® DIN Simul8
• Arduino Opta® WiFi
• USB-C® cable
• 24 V power supply with barrel plug adapter
• 8x wire for signal
• 2x wire for power distribution

Software

• Arduino IDE 2

Overview

DIN Simul8 is a digital-input-simulator and power distribution board for the PLC of the Opta family. It provides eight toggle switches (0 - 10 V output) and four screw terminal for bringing the 24 V and the GROUND easily to the PLC or other boards.

If you have any problems using the Opta WiFi you can read its manual before proceeding.

Connections

To connect the DIN Simul8 to the PLC you'll need 8 wires for the signal and two for the power.

Connections are super important in an industrial project, first of all disconnect the power plug and then connect all the pins using cable with lugs, or be careful that no copper part of the cable touch other pins.

1. Connect the power pins: +24V and GND
2. Connect all the signal pins

Upload Test Code

Firstly we have to test if the components and the connections works as excepted. Let's print on the Serial Monitor what arrives to the inputs.

The Opta WiFi has eight inputs ports, at the top, named from

I1

I8

A0

A7

Copy
1#define pin_I1 A0

I1

A0

PIN_A0

pin_I1

I2

A1

PIN_A1

pin_I2

I3

A2

PIN_A2

pin_I3

I4

A3

PIN_A3

pin_I4

I5

A4

PIN_A4

pin_I5

I6

A5

PIN_A5

pin_I6

I7

A6

PIN_A6

pin_I7

I8

A7

PIN_A7

pin_I8

From now on we can refer to the port

I1

pin_I1

To read what's arriving on each input port, we can use the digitalRead function, inside the

Serial.print

Copy
1Serial.print(digitalRead(pin_I1));

Now let's do this for each input port, dividing each value with a comma

,

Copy
1#define pin_I1 A0
2#define pin_I2 A1
3#define pin_I3 A2
4#define pin_I4 A3
5#define pin_I5 A4
6#define pin_I6 A5
7#define pin_I7 A6
8#define pin_I8 A7
9
10void setup() {
11  // put your setup code here, to run once:
12
13  Serial.begin(9600);
14
15}
16
17void loop() {
18  // put your main code here, to run repeatedly:
19
20  Serial.print(digitalRead(pin_I1));
21  Serial.print(",");
22  Serial.print(digitalRead(pin_I2));
23  Serial.print(",");
24  Serial.print(digitalRead(pin_I3));
25  Serial.print(",");
26  Serial.print(digitalRead(pin_I4));
27  Serial.print(",");
28  Serial.print(digitalRead(pin_I5));
29  Serial.print(",");
30  Serial.print(digitalRead(pin_I6));
31  Serial.print(",");
32  Serial.print(digitalRead(pin_I7));
33  Serial.print(",");
34  Serial.println(digitalRead(pin_I8));
35
36  delay(100);
37}

Don't forget to initialize the Serial communication with the Serial.begin command in the setup.

Don't forget to call the the last

Serial.print

as

Serial.println

, in order to print a new line and wrap the text to make readable.

Don't forget to put some delay, like 100ms in order to have a stable communication over serial.

Each switch in the DIN Simul8 outputs 0 V when OFF and 10 V when ON. The

digitalRead()

The output should be like this:

Upload Function Trigger Code

If everything works we can move on and try to trigger a function when switch change state: a function that print

"Switch 1 ON"

Copy
1void ON_function() {
2  Serial.println("Switch 1 ON");
3}
4
5void OFF_function() {
6  Serial.println("Switch 1 OFF");
7}

In order to make every function runs once, only when the state changed, and not continuously, we can save the status of the switch in a variable:

Copy
1bool stateSwitch = false;

and call the function when it reads the opposite state: if the state is OFF (0) and it reads ON (1) it means that is just changed to ON, so call the

ON_function()

stateSwitch

Copy
1if (stateSwitch == 0) {
2    if (digitalRead(pin_I1) == 1) {
3      ON_function();
4      stateSwitch = 1;
5    }
6  }

The final code should like like this and it will works only for the toggle switch 1.

Copy
1#define pin_I1 A0
2#define pin_I2 A1
3#define pin_I3 A2
4#define pin_I4 A3
5#define pin_I5 A4
6#define pin_I6 A5
7#define pin_I7 A6
8#define pin_I8 A7
9
10
11void setup() {
12  // put your setup code here, to run once:
13
14  Serial.begin(9600);
15}
16
17bool stateSwitch = false;
18
19void loop() {
20  // put your main code here, to run repeatedly:
21  
22  if (stateSwitch == 0) {
23    if (digitalRead(pin_I1) == 1) {
24      ON_function();
25      stateSwitch = 1;
26    }
27  } else {
28    if (digitalRead(pin_I1) == 0) {
29      OFF_function();
30      stateSwitch = 0;
31    }
32  }
33
34}
35
36void ON_function() {
37  Serial.println("Switch 1 ON");
38}
39
40void OFF_function() {
41  Serial.println("Switch 1 OFF");
42}

Upload Final Code

In order to make it works for all the eight switches, you can repeat the

stateSwitch

if-else

The idea is to replace all the variables used in the loop with arrays that stores eight values, one for each switch, and put it inside a

for loop

First of all we need an array for all the pins definition of the inputs:

Copy
1int pins[] = { pin_I1, pin_I2, pin_I3, pin_I4, pin_I5, pin_I6, pin_I7, pin_I8 };

Then we need one for the

stateSwitch

Copy
1bool stateSwitch[] = { false, false, false, false, false, false, false, false };

And then we can substitute them:

Copy
1if (stateSwitch[ ] == 0) {
2  if (digitalRead(pins[ ]) == 1) {
3    ON_function();
4    stateSwitch[ ] = 1;
5  }
6} else {
7  if (digitalRead(pins[ ]) == 0) {
8    OFF_function();
9    stateSwitch[ ] = 0;
10  }
11}

Now we need to tell to each array-variable which values to use, you can do it by putting a number from 0 to 7 inside the

[]

pins[0] = pin_I1 // pins[1] = pin_I2 // etc..

for-loop

int i

Copy
1for (int i = 0; i <= 7; i++) {
2  if (stateSwitch[i] == 0) {
3    if (digitalRead(pins[i]) == 1) {
4      ON_function();
5      stateSwitch[i] = 1;
6    }
7  } else {
8    if (digitalRead(pins[i]) == 0) {
9      OFF_function();
10      stateSwitch[i] = 0;
11    }
12  }
13}

Ok, that would work, but the

ON_function()

OFF_function()

i

Here the full code:

Copy
1#define pin_I1 A0
2#define pin_I2 A1
3#define pin_I3 A2
4#define pin_I4 A3
5#define pin_I5 A4
6#define pin_I6 A5
7#define pin_I7 A6
8#define pin_I8 A7
9
10int pins[] = { pin_I1, pin_I2, pin_I3, pin_I4, pin_I5, pin_I6, pin_I7, pin_I8 };
11
12void setup() {
13  // put your setup code here, to run once:
14
15  Serial.begin(9600);
16}
17
18bool stateSwitch[] = { false, false, false, false, false, false, false, false };
19
20void loop() {
21  // put your main code here, to run repeatedly:
22
23  for (int i = 0; i <= 7; i++) {
24    if (stateSwitch[i] == 0) {
25      if (digitalRead(pins[i]) == 1) {
26        ON_function(i);
27        stateSwitch[i] = 1;
28      }
29    } else {
30      if (digitalRead(pins[i]) == 0) {
31        OFF_function(i);
32        stateSwitch[i] = 0;
33      }
34    }
35  }
36}
37
38void ON_function(int n) {
39  Serial.print("Switch ");
40  Serial.print(n+1);
41  Serial.println(" ON");
42}
43
44void OFF_function(int n) {
45  Serial.print("Switch ");
46  Serial.print(n+1);
47  Serial.println(" OFF");
48}

And here you can see what's goes on the serial monitor when you turn on all the switch from 1 to 8 and then off from 8 to 1:

Considerations

If something strange happens when you turn a switch on or off, like if the switch was triggered on and off super rapidly, don't panic! That's normal, and it is related to something called "debounce". You can have a look here to understand what's going on.

Conclusions

The Arduino DIN Simul8 is the perfect playground to start experiment your coding skill in the PLC world. Try creating more functions that could be triggered by some combination of switch position, or whatever you like, have fun!