Basic example of Timer Contact with IECuino
In this post, we are going to see a super basic example of Timers, which is the Timers Example I of this blog, but before we start to explain it…can you differentiate Counters and Timers? We are going to explain to you what Timer means so easily.
As the name suggests, the Timers take into account the milliseconds that you indicate in the Preset Time* box.
The operation is as follows:
1. The current arrives at the TON Contact (Timer).
2. It starts to count the milliseconds that it is indicated on the Preset Time* box.
3. When it finishes, it will enable the current to the variable that is associated.
Representation of the performance process
So, let’s start with the Timers Example!
This mini-project aims to turn on and off a light or in our case an LED, with a START button. Keep in mind that this Ladder Diagram is only useful for one time, i.e., you can only use this Ladder one time.
Variables of this Timers Example I
First of all, we are going to explain the variables. In this case, there are:
· Pin 4: The name of this variable is pin 4 of the Arduino board. In our case, it will be a START button.
· lightPath: It is a “memory” variable that connects and associates the first TON (Timer), located in the first rung, with the N.O. of the second rung.
· light: its name indicates perfectly its function. It is the variable that turns on the light or the LED.
· LED_Killer: this variable is assigned to the N.C. contact, placed at the second rung. It turns off the light.
Secondly, we are going to see how is the performance of the Ladder Diagram.
1. At the first rung, we found the pin4 variable, which is a Normally Open Contact. The reason is that when the rail has current and the START button is pressed, the pin4 variable will activate.
2. Secondly, there is a TON (Timer), which is going to count up to 1 millisecond (0,001 seconds).
3. After pressing the button, the TON Contact will activate the lightPath variable, which will energize the first contact of the second rung, because it is a “memory” variable, which means that it is associated with the previous TON Contact.
4. Then, the current will find the Normally Closed Contact, that by default will let the current flow.
5. Afterwards, the light variable, which is and Output Coil, will activate. The first time that current arrives to this Output Coil, the LED will turn on because the Coil is associated with the light variable, which is mapped to pin 13, an output of the board. When the Coil is activated, the N.O. light variable of the third rung will also activate.
6. Finally, next to the light variable of the third rung, there is another TON Contact, which will count up to 5000 milliseconds (5 seconds) and the state of the LED_Killer variable will change from FALSE to TRUE. Subsequently, the Normally Closed Contact (second rung) associated with the LED_Killer variable will open, so the current flow will stop.
Information to consider
The LED_Killer variable, which as we know it is an N.C. Contact, will act as a STOP current because, after 5 seconds, the LED will turn off.
Requirements for the connection
- 1 Bread-board
- 1 Arduino board (in our case, an Arduino Leonardo board)
- 3 resistors of 10 Ω (Ohms)
- 2 push buttons
- 1 LED light
- 7 dupont wires
- 1 USB micro