Ardbox Relay Communications pinout configuration
Ardbox Relay PLC integrates the following communications.
- USB: Intrinsically available.
- I2C: Enable SCL and SDA connections (actual Arduino pins) with configuration switches. I0.0 and I0.1 not available. In order to implement this communication a 4.7kΩ pull-up resistor (IS.ACI2C-4.7K) is required.
- RS232: Enable RX and TX connections with configuration switches. 2 and I0.3 not available.
- RS485: Enable RE/DE/DI and RO internal pins with configuration switches. R1, R2, R5 and R6 not available. The defined Arduino Mega pins are showed in the chart below.
- SPI: Enable pin 7, 4, 3 or 2. I2C or RS485 not available.
In LEFT Zone and TOP Zone switches the communications for Ardbox Relay can be enabled
LEFT ZONE. To enable communication connections the switchs must be set to “OFF”. Set to “ON” position to enable I/Os PLC connection. Communications and I/Os on the chart can not work simultaneously. For exemple if DE is enabled (OFF), R1 will not work. OFF position provides direct connection to Arduino Pin (NOT for TX and RX), so they can be programmed according to Arduino pin features.
TOP ZONE. Communications and relays can not work simultaneously. If R6 is enabled RO must be disabled and conversly.
Go to Ardbox Relay Store page.
Hardware selection is very important when you try to develop projects where sensors, actuators and PLC´s must talk each other. For this project, with chosen the following equipment:
- PLC: Any PLC from IndustrialShields is a good option. We have chosen the M-Duino PLC Arduino 21 I/Os Analog/Digital because we think it has different communication options to be communicated with other systems (Ethernet, RS232, I2C…).
- Panel PC: For this project, we are going to visualize and control our installation with the HummTouch 10.1” Linux panel pc.
- Humidity sensor: Probably, when you try to develop an application like we are trying to, the most important selection is the sensor itself. There are a lot of humidity sensors available around the market completely compatible with Arduino based hardware. We´ve chosen the SHT10 sensor from Adafruit because it includes a temperature sensor as well, it comes with an intermetal mesh encasing, which is weatherproof and because it is designed to be submersible in water.
- Others: A relay to activate the irrigation system, a 24Vdc power supply, a good enclosure to protect the equipment and cables are important things to keep in mind too.
To develop the project, the first thing to do is to ensure that we have the proper software and libraries. As we are going to use the SHT10 sensor, we will use the SHT1x library that you can download in the following link: https://github.com/practicalarduino/SHT1x. SHT10 uses a two wire communication interface similar to I2C. As usual, we will use the Arduino IDE to develop the software. You can download it here: http://www.arduino.cc/en/Main/Software. You can see the code in the following file: Key benefits There are a lot of benefits to implement a humidity control in an irrigation system. Let´s see the most important:
- Saves Time: Automation does the job for you, so you can go on holidays knowing that your flowers will be maintained when you come back.
- Saves Money: No more water wasted, automation guarantees efficiency: water is used when is needed.
- Improves Growth: An irrigiation system guarantees flowers waterd with proper amount of water. In a reasonable time, you will have a greener garden.
User guide M-duino family products: (checks the date of purchase of your computer to view previous versions)
You can download your Arduino IDE.
Have you got any analog signal 4-20mA? See the diagram below to know how to connect a 0-10Vdc Analog input.
- Ardbox Analog or Ethernet PLC family products have some configurable Analog/digital input. It is necessary to connect an impedance of 500 ohms between the 4-20mA analog signal and the ground signal. If you do that, the Analog value will be changed.
How is changing the Arduino input value
When you have a 4-20mA for 10bits you get these values:
but, if you convert this signal to 0-10Vdc, the results are:
204 value* (aproximately)
As a continuation of the Air-conditioning system post, in today´s newsletter Opiron suggests to expand the HVAC system controlled through the Touchberry Pi Panel PC and Ardbox Relay from IndustrialShields. As the last post, the suggested SCADA that will run on the Touchberry Pi is the following: myscadatechnologies.com Summarizing the previous post, we designed a system that was able to activate the air conditioning with a relay. In order to expand the system, we will include the following sensors to have a complete automatic HVAC system:
- Inside temperature.
- Outside temperature.
- PID development in order to control the inside temperature (the relay will be controlled by the PID loop).
Additionally, the air conditioning system will be integrated into a complete home automation solution where the Scada will give us access to a light system control, open and close windows, and security cameras. Software and code: Inputs and outputs definition
What are inputs and outputs from the coding point of view? As inputs we will consider the inside and outside temperature. As output, the relay that activates the air conditioning that we already programmed in the last post. As mentioned in the last post, the SCADA is owned by myscadatechnologies.com. Its main advantages are that is Open Source based, and very easy to be used. We will use I2C to communicate the SCADA and the Ardbox PLC. The code to be uploaded is the next one: SCADA design: Control Screen
Once we have already defined PLC programming, it is time to define the screen we will make the interaction between man and machine (HMI). Designing SCADAs really forces us to simplify and decide what’s most important- what needs to stay on the screen. As we want to implement an easy to use temperature control screen, we will show a thermometer with the actual temperature inside, and 4 big windows to see the basic features of the system. The first window with the temperatures inside and outside, at right, the system status window to have an easy access to alarms and other parameters, and below the temperature PID´s, one for the day and the other one for the night. At the left of the screen we will have a menu to access to the other parts of the system (lighting, temperatures, windows, cameras and service). Key Benefits
The main benefits of the this suggested solution are:
- Automatic temperature regulation: The relay is now controlled by the PID!
- Scalable system: The purposed system permits to connect multiple devices to the Touchberry Pi.
- Open Source based: 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.
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.