DMC created an MQTT driver that bi-directionally connected the PLC to a cloud based broker. MQTT is the industry standard for most IIoT applications and works on a simple TCP connection. For security and connection robustness the connection from the PLC to the cloud was established within an OpenVPN. The MQTT driver sends and receives data between the PLC and our application on Azure and gives the framework for controlling the system in the field. The broker in the cloud receives the data from the plcs and directs the data to the correct application, and also receives commands from the website and transmits the information down to the PLC.
We then made a protocol gateway that communicated the relevant information from the MQTT service to the correct location in the cloud through an Azure IoT Hub. The MQTT messages were received in the cloud by the broker service, which parsed the data through the gateway for storage in to our SQL cloud database. The gateway is also capable of receiving commands from the website via the API and passing the commands to the PLC.
Finally, DMC built a custom REACT webpage with all the same functionality as the system's HMI screen on site, as well as a few additional features. The webpage provides a complete user experience with all controls and functionality for the PLC. The website includes access to user administration, additional units of measurement, and the ability to see historical data including flow rates, pressures, alarm logs, setpoints, and usage. The webpage interacts with the API to send and receive data from the cloud database.
DMC trained the client on emerging technologies that are available and guided them toward a more high-tech yet cost effective solution. Additionally, we trained the client on using the custom REACT website we built, the capabilities of the technologies used, and on debugging and troubleshooting.
The customer was also working with multiple other vendors and clients, and DMC navigated communication challenges to manage and complete the project. Finally, we accommodated scope changes and completed additional programming to add features relevant to the client.
Learn more about DMC's PLC Programming Services and Application Development expertise.