Manufacturing drinking water is a process with different steps. The last step is called disinfection, used to destroy microorganisms in water. To achieve it, systems inject chlorine. This technique is called dosing. Dosing is the technique for controlling the addition of a substance to a flowing liquid or gas. Dosing systems are designed to achieve the required dosing level by maintaining the control signal as a proportion of the fluid flow rate. In this post we are going to develop a chloride dosing system based on Arduino.
Dosing control equipment consists basically of the following elements:
- A controller, in this case we will use an M-Duino PLC.
- A flowmeter.
- A dosing pump.
- A dosing level sensor.
The following figure shows the general arrangement of the dosing control system: The dosing concentration measured by the dosing level sensor is used to stop the pump if a there is high concentration in the tank. The flowmeter provides the input of the control loop, which is connected to the pump (as the output).
Software and code
In this example, dosing level and flowmeter are configured as a 0-10V analog input. The pump works with a frequency driver. As we have to develop a control loop, we have created a PID controller linked to the specified input, output and setpoint. You can find the code to be uploaded here:Key Benefits
The main benefits of the Opiron – Industrial shields proposed solution are:
- Flexibility: This application note describes how the Open source based hardware can be used to control the dosing level of a chlorine system. However this same architecture can be used with any liquid or gas using the PID algorithm.
- Freedom to modify your software: You aren’t limited to what one company believes you need.
- Easy to be integrated: No matter if you already have an automation system. The Arduino hardware is easy to integrate into your system..
Do you have a process to be automated? Contact Industrialshields to implement the entire solution and to buy the proper hardware.
Packaging machines are used to enclose and protect products for distribution, sale, and use. They are very popular in industry because they are safe, reliable, and usually integrated into the process line. They guarantee a big productivity.
Our packaging machine will have three basic control functions: HMI( the Human Machine Interface), PLC (the logic part of the control), and the Motion Control functionality. The main idea of the Project is to develop a reliable and flexible machine. We will make use of an Ardbox Relay as the main processor of the system, but, as packaging machines need to be integrated into more complex systems, as we saw in the Feeding a packaging machine with a frequency driver post, we will make use of an M-Duino PLC, which has Ethernet connectivity which can send data to an SCADA. The detailed hardware can be found at IndustrialShields the website.
Hardware and Operation
In this newsletter we are going to show just a part of the packing machine. This is a feeder and the lifter. The feeder consists of a piston, when a product is in front of the feeder, the feeder moves forward and the lifter downs a level. When the lifter is at the lower level, the entire product can be sent to the packaging part. The hardware components will be:
- Five mechanical switches (Reverse, forward, upper switch, middle switch and lower switch).
- 4 relays which are based in Arduino. 2 of them for the feeder (forward and reverse movement) and 2 more for the lifter (up and down movement).
Software and coding
As described above, the system works in six steps. Furthermore, the code has an additional but interesting feature: the capability to receive commands from another PLC (M-Duino), if an operator wants to stop the process remotely. Download the Arduino source code in the link below:
- Remotely control from another PLC capability.
- Open Source hardware based, which it means reliable, cheap and expandable.
- Easy to be installed.
HVAC systems usually have an available contactor that will allow us to connect a relay. Connecting the relay to an Ardbox Relay PLC, and the PLC to the Touchberry Pi, we will be able to control climate conditions remotely. In this project, Opiron Electronics proposes to make a basic control system with an interface that will enable us to activate the HVAC system remotely with the Ardbox Relay PLC and the Touchberry Pi HMI, both from IndustrialShields. The purposed SCADA that will run on the Touchberry Pi is the following: http://www.myscadatechnologies.com/
Hardware and communication
We are going to use:
- An Ardbox Relay PLC: This is a 18 digital inputs / outputs Arduino based PLC that offers the possibility of communication between two computers using I2C. For more details, see the following link.
- A Touchberry PI 10.1″: The Touchberry Pi is a 10.1″ panel PC designed to work in industrial environments and based on the popular Raspberry Pi. For more details, see the following link.
To communicate both devices, we will make use of the I2C communication. The main advantage to use this protocol is its flexibility as you can easily connect up to 128 slaves to the Touchberry Pi. See below the Software explanation for more details on how to do it.
Software and code
As mentioned above, the purposed SCADA is owned by myscadatechnologies. We’ve chosen this SCADA because it is open source, available to be downloaded and tested on Raspberry Pi, which is Touchberry Pi processor based. Since the communication point of view, I2C needs one Master. The other device will be the slave. The Ardbox PLC Relay will be the slave and the Touchberry Pi the master. Regarding the Ardbox Relay, the code to be uploaded is the next one:
When the command received from the scada is activated, we will activate the relay. Regarding the Touchberry Pi software to be developed, basically, as well as installing the scada on our Touchberry Pi, we have to set it as a master in the I2C developed network, but before we need to enable the I2C module on the PI.
- As root edit /etc/modprobe.d/raspi-blacklist.conf and comment out the line blacklisting i2c-bcm2708
Next add i2c-dev to the /etc/modules file so it’s loaded on boot:
Finally install i2c-tools:
Finally, reboot the Touchberry Pi.
The main benefits of the Opiron purposed solution are: – Scalable system: The purposed system permits to connect multiple devices to the Touchberry Pi. – Open Sourcebased: This feature means big flexibility, big availability of resources on the internet in case of failures or change implementations, etc. – Remote control: Control climate conditions through an HMI panel.
POWERED BY OPIRON ELECTRONICS
This project was undertaken to ensure the supply of a treatment plant for waste water purification. This required the correct filling of the tank that was responsible for providing the Dirty water. 2014111_Tratamiento_de_aguas
Ardbox is an easy, compact and economical way to automate your installation
- IN: Ardbox Analog Signal
- Full level Gravity filling tank (Digital input “24Vdc”) I0.1
- Minimum level of Gravity filling tank (Digital input “24Vdc”) I0.2
- Level of storage tank (Analog input “0-10Vdc”) I0.9
- Auto/Manual Selector (Digital input “24Vdc”) I0.3
- Regulator quantity of Acid (Analog input “0-10Vdc”) I0.8
- Regulator quantity of Flocculant (Analog input “0-10Vdc”) I0.7
- Ok water into processing plant ( Digital input “24Vdc”) I0.4
- Grinder pump (Digital output “ 24Vdc”) Q0.5
- Acid dosing PUMP (Analog output “0-10Vdc”) Q0.6
- Filling pump to processing machine (Digital output “24Vdc”) Q0.4
- Flocculant dosing PUMP (PWM output “24Vdc”) Q0.3
- Full level Gravity filling tank (Digital output “24Vdc”) Q0.2
- Air Electrovalve (Digital input “24Vdc”) Q0.7
- Red Light (Manual MODE) Q0.8
- Green Light (Auto MODE) Q0.9
Ardbox is an Arduino based PLC for Industrial use. Most of the industry sensors work at 24 Vdc. As the standard ARDUINO works at a voltage of 5Vdc and 3.3Vdc depending on the different devices this in principle makes impossible its usage on industrial environments. This is the main reason why Industrial Shields has adapted the Arduino Industrial original electronic in order to let them work at 24Vdc and it has also has made sure that it meets all the requirements and industrial regulations.
The initial Arduino PLC developed by Industrial Shields are:
Each one of these devices looks for the maximum Arduino performance, being possible to be used as an industrial machine controller, automation processes, control systems, etc… Furthermore, if there is a need of a combination of the different Arduino PLCs, it is possible to use them in Master – Slave mode as the whole Ardbox family is prepared in order to offer a better and optimized control and communication with the machinery.