IRIV PiControl as IoT Gateway at SHRDC (Selangor Human Resource Development Center)

By Dr. Chua Wen-shyan

Selangor Human Resource Development Centre or SHRDC is a not-for-profit training and talent development centre established by the industry and government in 1992 to appropriately skill Malaysians for a sustained and addressable pool of high-impact talents for companies and businesses.

IRIV as the IoT Gateway

The training kit utilizes IRIV PiControl is used as a data acquisition device and an IoT gateway. It performs the following functions:

• Data Acquisition:
  • Receives signals from switches and RS485 sensors.
  • These signals can be individually collected or grouped (e.g., all switch signals, all LED signals, etc.).
  • So far, there is no pre-processing of data that is done before logging. Nonetheless, that can be done if needed to formulate the necessary key parameters for machine, process, and/or production efficiency and effectiveness monitoring.
• Data Transmission:
  • Sends received data to both the laptop/computer and the cloud for logging.
  • Uses a wireless connection (WiFi) for communication with the laptop/computer.
  • IRIV PiControl provides the flexibility of connection to the Internet and machines. With dual Ethernet ports, we can utilize one for Internet access, sending data to the cloud. Another Ethernet port for Machine interface like Modbus TCP/IP. 
  • In some cases, WiFi/Wireless connection is not permitted in some manufacturing facilities, the dual Ethernet ports come in handy!

Overview of SHRDC Training kit with IRIV PiControl

The Actual Training Kit

The training kit is assembled in a plastic enclosure with a transparent top cover. There are two DIN Rails for equipment mounting and proper wire trunking. The transparent cover provides the visibility of the whole system and also the status of some devices (for example LED indicators on PSU, IRIV PiControl, and also on the Relay modules)

The IRIV PiControl is mounted on DIN Rail, powered by a 24VDC Meanwell PSU (also DIN Rail mountable).  All wires are terminated with the ferrule, and the 24VDC is labeled properly. 

The switches (Digital Input to IRIV PiControl) and LED indicators (Digital Output from IRIV PiControl) are mounted on the transparent cover. There is also an emergency switch that will cut off the 24VDC supply to IRIV PiControl. 

Node-RED as the Software Platform

The training kit relies on Node-RED for its software functionality. This choice was made due to the following reasons:

• Continuity: Node-RED was previously used for data pulling and pushing in their current gateway, and maintaining consistency in the methodology simplifies the implementation and introduction of IRIV to the industry and community.
• Ease of Use: Node-RED offers a user-friendly visual programming interface, making it suitable for beginners and experienced users.

Signal Flow and Programming

The project separates signal flow and programming into two distinct domains:

• Signal Flow:
  • Switches to Cloud: Switch signals are directly sent to the cloud for logging.
  • The same goes for the status of LED, it is logged into the cloud too. 
• Programming:
  • However, the logic for switching signals and how the LED works is programmed locally on the laptop/computer. This allows for flexible modification without affecting the nodes in IRIV PiControl.

With local programming, it provides advantages: 

• Flexibility: You can easily modify the programming for switches and LEDs without reconfiguring IRIV PiControl or the Cloud.
• Convenience: Programming can be done directly on the laptop/computer, eliminating the need for additional hardware or software.

However:

• MQTT Broker Dependence: An MQTT broker is required to establish communication between IRIV PiControl and the laptop/computer.
• WiFi Requirement: WiFi connectivity is necessary for communication between IRIV PiControl and the laptop/computer.

Learning Outcomes:

Participants will learn about:

• The basic setup of IRIV PiControl - hardware and also software.  
• MQTT Protocol: The MQTT protocol facilitates communication between devices in an IoT ecosystem.
• Cloud Data Logging: Understand how data is collected and stored in the cloud for further analysis and visualization.