The article explores how Industry 4.0 leverages technologies like RFID, M2M communication, and IIoT for seamless data exchange, enabling real-time tracking, automation, and secure, efficient manufacturing processes.
The central theme to Industry 4.0 is the gathering and sharing of information. The data describing the location of the raw material, the part being assembled, the operating parameters of the equipment, and the environment in which it is being manufactured are constantly being collected and analyzed. This widespread data collection is done through many different ways, based on the task and the environment. The most common methods include radio-frequency identification (RFID), machine-to-machine (M2M), and Industrial Internet of Things (IIoT). In many cases, a combination of these methods is utilized.
Radio-Frequency Identification (RFID)
Bar codes have been used to track items for many years. However, in order for the bar code to be read, it must be facing the bar-code scanner. The proper orientation of the object, along with a clear view of the scanner, is required for the bar code to be read. Radio-frequency identification is a wireless system where the digital data are read from an RFID tag through the use of radio waves. The RFID tag does not need to be facing the antenna. Other items or materials can be located between the RFID tag and the antenna.
The use of wireless technology instead of an optical scanner has broadened the applications in the industrial setting. RFID systems typically operate at frequencies between 900 and 915 MHz. Examples of a bar-code tag and an RFID tag are shown in Figure 1.
Figure 1. Bar-code tag and RFID tag.
Passive RFID Tags
The tags come in two categories: passive and active. The passive RFID tag collects energy from the radio waves and uses it to power a tiny circuit inside the tag. The circuit sends out a preprogrammed digital identification signal that is read by a RFID reader. The RFID reader receives the data and passes it on to a computer system, where it is stored in a database, as shown in Figure 2.
RFID tags are attached to a product as it begins the automated assembly process. Each automated cell has an RFID reader. This allows the computer system to track where the product is on the assembly line. The RFID tag can be attached as a sticker or embedded in a plastic housing. The passive RFID tag has a working distance of 30 feet or less.
Figure 2. RFID system.
Active RFID Tags
The active RFID tag adds two more sections to the passive RFID tag: power supply and additional electronics. The power supply is typically a battery. However, small solar panels are sometimes used in place of the battery. The additional electronics can include a microcontroller, memory, sensors, and input/output ports.
The addition of the sensors and microcontroller in the active RFID tag opens up more uses for the tag. Not only can it be used to track a product, it can also monitor the condition of the product with the on-board sensors. The active RFID tags have a working distance in excess of 300 feet.
The active RFID tag is available in two formats: beacon and transponder. The RFID beacon style tag transmits a signal containing specific information every few seconds. When the beacon RFID tag is within range of a reader, that information is captured. Due to the repetitive transmissions, the battery life is reduced. To offset the reduction, the output power of the transmitter is typically less than that of the transponder.
In the RFID transponder configuration, the signal is initiated once the RFID tag receives a signal from the reader. This format conserves battery life and allows for a higher output power for the transmitted signal. The transponder has a greater range than the beacon configuration.
Both passive and active tags are available in read-only and read-write formats. The read-only RFID tag is programmed once and the data are not able to be changed. The read-write tag allows the data on the RFID tag to be updated while the tag is in use.
Internet of Things and Industry 4.0
The Internet of Things (IoT) comprises devices connected together through the Internet that were not previously connected to the Internet. A great example is the home thermostat. The thermostat that regulates the temperature in your home has evolved from a static device to a programmable device, to an Internet-accessible programmable device. Instead of having to be physically present to program or adjust the thermostat, it can now be programed and controlled via the Internet.
The IoT thermostats all come with an app for a smart phone. Through this app, the thermostat can be programmed and controlled directly. The home use of IoT devices includes light bulbs, thermostats, doorbells, wall outlets, smart TVs, smart speakers, and garage door openers.
Devices outside of the home are also being added to the Internet. The list of devices includes street lights, security cameras, and electric meters. The list of Internet-accessible programmable devices continues to expand every day. The main purpose of IoT devices is convenience for the user in the completion of common tasks. For example, changing the room temperature, checking to see if the garage door is open, and controlling the lights in a room through voice commands are some of the tasks that can be accomplished with an IoT device.
Machine-to-Machine Communication in Industry 4.0
Programmable logic controllers, smart sensors, robots, conveyor lines, and machining centers can be programmed to act on the information received from other devices. This type of communication is called machine-to-machine (M2M) communication.
In automated processes, the majority of communication takes place between machines without the need for human interaction. The M2M networks are designed to carry the information exchange between the programmable logic controllers, the sensors, the robots, and the machining centers on the manufacturing floor.
The M2M networks can be hardwired or wireless. A central computer system communicates with the programmable logic controllers, which in turn communicates with their associated sensors, conveyors, robots, and machining centers, as shown in Figure 3. The central computer system tracks the status of the devices on the network and provides a means for the data from these devices to be accessed.
Figure 3. M2M communication.
The centralized process management system of remote devices and automated systems provides a wealth of data and facilitates informed decision making in the manufacturing process.
The requirement of a hardwired connection between devices and the central computer system was a limiting factor. Advances in wireless communications provided a means for communication between the central computer system and the devices. The current M2M communication takes place over the Industrial Internet of Things (IIoT).
Industrial Internet of Things
Interconnectivity through the Industrial Internet of Things (IIoT) requires the devices to maintain a secure network connection. The IIoT can share data between devices with differing protocols through the use of an internal cloud. The strict security requirements of manufacturing data set the IIoT apart from the IoT. To maintain a high level of data security, the IIoT utilizes an internal cloud maintained by the manufacturing facility. In comparison, the IoT utilizes an external cloud to exchange and house data.
The secure network provided by the IIoT provides for a wireless network environment in which the automation systems can communicate across manufacturing platforms. All of the data gathered can be analyzed to provide improved efficiency, an efficient use of resources, a safe and efficient use of workers, and data-driven decision making.
The IIoT devices utilize various technologies to share data with other connected devices. These devices require a high level of network security. The data is commonly stored on an internal cloud for use by multiple departments within the manufacturing facility.
The network connection between the IIoT device and the industrial network at the manufacturing facility must remain secure to prevent unauthorized access to the network. The industrial manufacturing data must be kept secure, along with access to the industrial network. If a computer hacker gained access to the industrial network, they could stop production and demand a ransom payment, or they could sell the data to the company’s competitors.
In Industry 3.0 devices such as robots, sensors, and control devices were originally connected to the programmable logic controllers by pairs of wires. Each device had its own set of wires running back to the programmable logic controller. This evolved to programmable logic controllers connected to a local network. The robots, sensors, and control devices all connect to the same network and share their information with the programmable logic controllers through M2M communication.
In Industry 4.0, this evolved into data sharing between all devices on the network. Not only can the individual programmable logic controllers communicate with the devices on the network, they can also communicate with other programmable logic controllers within the manufacturing process. The smart sensors used by the automated systems contain internal processing circuitry that allows them to be programmed to respond to various situations. For example, if a photoelectric sensor using a redundant sensor system determines one of its sensors has a dirty lens, it will alert the programmable logic controller. The programmable logic controller issues a work order through the company-wide network, and a technician is dispatched to clean the sensor lens. The smart sensor continues to function using the second photoelectric sensor, ensuring the manufacturing process continues to operate. The smart sensors help reduce machine downtime.
All of the data generated by these automated systems are shared with the other departments within the company through an internal cloud. This allows the entire manufacturing process to be monitored and interacted with through one main management system.
The Industrial Internet of Things facilitates the connection of the supply chain information to the main management system. The lead time for materials and supplies can be continuously monitored. The supplies are tracked live through the Internet from the time they are shipped until they are loaded into the automated processes at the manufacturing facility. This provides accurate production scheduling without the need for large warehouses filled with supplies.
Industry 4.0 Key Takeaways
The integration of RFID, M2M communication, and IIoT forms the backbone of Industry 4.0, driving smarter, more efficient, and highly connected manufacturing environments. These technologies enable real-time data exchange, automation, and enhanced decision-making, while ensuring security and flexibility across the production process. As Industry 4.0 continues to evolve, the ability to gather, share, and analyze data will remain central to optimizing resources, minimizing downtime, and maintaining a competitive edge in modern manufacturing.