How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain Disruptions

Logistics tracking is increasingly essential to manage the supply chain disruptions that are expected to continue for the foreseeable future. Logistics is the process of moving items from one place to another: within a manufacturing facility or a warehouse or between geographically dispersed locations. Logistics tracking provides a real-time supply chain status, enabling adjustments to be made as needed to minimize the impact of supply chain disruptions and ensure smooth, efficient, and profitable operations.

The emergence of the industrial internet of things (IIoT) has resulted in the development of Logistics 4.0 and smart supply chain management, including artificial intelligence (AI) to address new challenges and bring added flexibility to logistics management. Logistics 4.0 enables real-time supply chain visibility and integrity control to ensure the availability of the information needed to deliver the right products, at the right time, place, quantity, and condition, and at the right cost. Depending on the location within the supply chain, logistics tracking can be implemented using an array of technologies, including; linear (1D) barcodes, 2D barcodes, radio frequency identification (RFID), near field communication (NFC), Bluetooth, Wirepas (industrial Bluetooth), and GPS technologies.

This article presents an overview of the logistics challenges, compares the utility of selected logistics tracking technologies and related industry standards, and closes by presenting examples of tracking tools from Banner Engineering and Würth Elektronik, along with an evaluation platform to speed the development process.

Industry 4.0 and Logistics 4.0 are interconnected, and both are needed to achieve the goal of efficient mass customization economically. Logistics 4.0 relies on highly granular and real-time information related to individual items, combined with networking, automation, and low-latency communication to provide early warnings of disruptions and enable rapid responses to maintain an optimal flow of goods throughout the supply chain. Multiple technologies are needed to arrive at the best logistics solution for a given situation.

1D and 2D barcodes

Barcodes are an inexpensive and effective way to automate data collection on individual items. Depending on the quantity of data, there are several barcode formats, including:

  • 1D or linear barcodes can contain information such as serial number, model number, and item history.
  • Stacked linear barcodes that use multiple 1D barcodes stacked closely together to deliver higher data densities.
  • 2D barcodes are composed of boxes or cells, with even larger amounts of data stored in a grid format.

1D barcodes are the most common, and the barcode information is contained in the width of the black and white bars and spaces and is read using a barcode scanner that understands the specific format being used. There are multiple formats of 1D barcodes that have been optimized for the data needed by specific applications. Some examples include:

  • Code 128, for material handling
  • Code 39, used by the military and government agencies
  • Interleaved 2 of 5, for specific industrial applications
  • UPC-A, widely used in retail in the U.S.
  • Postnet, used by the US Postal Service (USPS)

For example, the Code 128 format includes (Figure 1):

Bars are black lines that deliver the information. In basic codes, there are two bar sizes—wide and narrow—translated into binary information by a reader. Other code formats can include varying widths of bars and white spaces to communicate more details.

Quiet Zone is a blank space at the edges of the barcode to enable the scanner to identify the beginning and end of the code. It is a common feature in all 1D barcode formats.

Start and Stop Codes are specific combinations of bars and spaces that indicate the beginning and end of the barcode.

Check Digit is used to verify the accuracy of the data and protect against data reading errors.

Human Readable Code is not part of the machine-readable information in the barcode.

Module Width is the height/width of the smallest cell or bar in the barcode and determines the minimum resolution needed by a scanner to read the code accurately.

How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain DisruptionsFigure 1: Structure of a 1D barcode using the Code 128 format (colors are for identification only). (Image source: Banner Engineering)

2D barcodes are more complex and contain larger amounts of data. Some of the common 2D barcodes include:

  • DataMatrix used in automotive, electronics, and USPS applications
  • QR code also used in automotive, as well as commercial marketing
  • Aztec found on travel tickets and some vehicle registration documents
  • Maxicode used for material handling and by the United Parcel Service (UPS)

The DataMatrix format includes (Figure 2):

Cells are black and white squares areas inside the 2D matrix that contain the data.

Quiet zone is a blank space around the perimeter of a 2D barcode to enable the scanner to identify the beginning and end of the code.

Finder (or “L”) pattern orients the reader so it can identify the correct way to read the code.

Clocking pattern is on the opposite side of the finder pattern and tells the reader the size of the cells inside the code and the number of rows and columns in the barcode.

How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain DisruptionsFigure 2: 2D bar code DataMatrix structure (colors are for identification only). (Image source: Banner Engineering)

2D barcodes also contain error correction data. Depending on the code, the error correction data may be included three times to improve readers’ quality of data collection.

Reading barcodes

Laser scanners provide a simple and cost-effective way to read 1D barcodes. The laser is directed across the barcode using a rotating mirror, and the reflected light is measured using a photodiode. The light measurements are then translated into a digital output. High-speed laser scanners can perform up to 1,300 scans per second but cannot read 2D barcodes.

Imaging readers can be used to read both 1D and 2D barcodes. These readers capture an image of the barcode, which is analyzed using image-processing software that can locate, orient, and read the barcode. Compared with a laser scanner, an image reader has a wider depth of field for reading at multiple heights and can simultaneously read multiple barcodes. The speed of the reading process is dependent on the capability of the imaging camera and processing software.

Wirepas self-forming mobile networks

In addition to barcodes, wireless tags and the IIoT can be used to provide item identification, location and condition across the supply chain. Wirepas is an autonomous self-forming wireless connectivity protocol designed to deliver the scale and density needed to support Logistics 4.0 applications. Traditional mesh networks such as Bluetooth can struggle to reach large scales due to congestion and bandwidth limitations. Wirepas removes those barriers by decentralizing the network intelligence to the nodes, resulting in a self-healing network with collision-free radio spectrum usage (Figure 3).

How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain DisruptionsFigure 3: In logistics tracking applications with high numbers of items to manage, Wirepas can provide an alternative to Bluetooth or proprietary wireless protocols. (Image source: Würth Elektronik)

Wirepas Mesh software is designed for large-scale and battery-powered networks. Each node…

  • Scans the network environment and chooses the optimal path
  • Adjusts transmission power based on the proximity of nearby nodes
  • Can work as a routing or non-routing node, or a sink
  • Can switch between low power and low latency modes
  • Selects the optimal frequency
  • Is interference tolerant

The Digital Container Shipping Association (DCSA), an independent organization founded by several of the largest container shipping companies, has published wireless connectivity interface standards for shipping containers. Wirepas is compliant with the DCSA standard.

Implementing 1D and 2D barcodes

Designers can turn to the ABR3009-WSU2 WVGA (752 × 480 pixels) image-based barcode reader from Banner Engineering when designing Logistics 4.0 tracking systems using 1D or 2D barcodes (Figure 4). It’s factory-calibrated at three focus positions or 45 mm, 70 mm, and 125 mm, and it has a continuous focus range to provide fine-tuning for individual applications. The ABR3009-WSU2 can capture 57 frames per second.

Engineering” alt=”How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain Disruptions”>Figure 4: The ABR3009-WSU2 from Banner Engineering reads a full library of 1D and 2D barcodes. (Image source: Banner Engineering)

All standard 1D and 2D ABR 3000 series readers are set to read DataMatrix barcodes and can be easily configured to read other styles using on-board push buttons for simple configurations or with a PC using Banner’s Barcode Manager software for more complex configurations. Lens options, including software adjustable autofocus, can further simplify setup and configuration. Device integration and IIoT data collection can be configured over industrial Ethernet, serial or USB connections. The model ABR3009-WSU2 is IP65 rated, protected from dust, and from water projected from a nozzle.

Wirepas radio module

The Thetis-I from Würth Elektronik is a 2.4 gigahertz (GHz) radio module that supports the Wirepas mesh communication protocol. Designers can use part number 2611011021010, with a line of sight range of 400 meters (m), to integrate Wirepas into Logistics 4.0 asset tracking devices (Figure 5). It has a transmission (Tx) power of 6-decibel meters (dBm), a reception sensitivity (Rx) up to -92 dBm, and a transmission rate up to 1 megabit per second (Mbps). The 2611011021010 requires 18.9 milliamperes (mA) in Tx mode, 7.7 mA in Rx mode, and 3.16 microamperes (µA) in sleep mode. It measures 8 x 12 x 2 mm.

How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain DisruptionsFigure 5: The 2.4 GHz Thetis-I radio module with Wirepas mesh protocol. (Image source: Würth Elektronik)

To speed the development of Logistics 4.0 applications using the Thetis-I radio module with Wirepas mesh protocol, designers can use the Thetis-I EV-Kit that includes a mini-EV board, a USB radio stick and three sensor nodes (Figure 6). An operating Wirepas mesh prototype network can be set up in a few minutes, and each of the components in the EDV-Kit (mini-EV board, USB radio stick, and sensor nodes) can be purchased separately to enlarge the prototype network.

How Logistics Tracking and Logistics 4.0 Can Manage Supply Chain DisruptionsFigure 6: The Thetis-I EV Kit is equipped with a Thetis-I Wirepas Mesh module and includes a mini EV board, a USB radio stick, and three sensor nodes. (Image source: Digi-Key)

The mini-EV board supports connection with a host microcontroller for application development. The sensor node is a 31 mm x 32 mm battery-operated board and includes a pressure sensor and a humidity sensor. Sensor data are automatically read by the radio module and transmitted to the mesh network. The EV Kit also includes Würth’s PC Tool Wirepas Commander software that supports communication with the radio modules, network configuration, and monitoring of sensor data.

Summary

Logistics 4.0 relies on real-time, granular information about all items in the supply chain and needs to be integrated with Industry 4.0 using networking systems, automation and low-latency communication to provide early warnings of supply chain disruptions. It takes multiple tracking technologies to implement a successful logistics system. This article has presented various choices related to 1D and 2D barcodes and highly-scalable wireless Wirepas networks that can work collaboratively in a Logistic 4.0 solution.