In the modern world, conditions have to be measured far away from computer networks. We need to know about weather in remote locations, soil conditions for crops, temperatures in vaccine refrigerators, and much more. Where does the data come from?

We will not put a computer network in a farmer’s field. Obviously, that wouldn’t work. We use data loggers to gather the information that’s uploaded to remote computer networks. 

Transportation and warehousing are areas where data loggers are most important. This is especially true in the cold chain — the supply chain where perishable items must stay at specific temperatures.

It’s common in the industry to divide all data loggers into two categories: passive and active loggers. Passive devices log data and require some action to be performed in order to load the data. Active loggers act “online” and provide real-time information.

What Is a Data Logger?

A data logger is an electronic device with an array of sensors. While these sensors can measure many conditions within supply chains, such as: 

• Temperature
• Light
• Humidity
• Shock

The logger stores the data before it’s transferred into a computer network. You can set loggers to transmit data in various time increments from seconds to hours apart. Most loggers run on battery power. Storage capacity and battery life are among the most important factors when determining which type of logger to use. 

How the data logger transfers its information to the computer network is one of the most crucial considerations when choosing a logger. You have many choices, such as: 

• USB Data Loggers
• Bluetooth Data Loggers
• NFC Data Loggers
• NFC/RFID Combination Data Loggers
• Cellular/Satellite Data Loggers
• E-Ink Dynamic QR Code Data Loggers
  

USB data loggers have long dominated the supply chain. This is changing. Risks associated with USB data loggers have led many to consider newer high-tech wireless data loggers. For the cold chain, a low-tech solution, QR codes may well be the best solution once you consider all the parameters. 

Data Loggers Used in Supply Chain Monitoring

When picking a data logger for supply chain monitoring, the first question to ask is what product the data logger will monitor. If it’s for monitoring a crate of nuts and bolts, the only necessary capability may be to determine the item’s location.

If the data logger is monitoring the transport of computer parts, shock will be important. Too much turbulence will damage fragile items. For food products that require refrigeration, temperature and humidity are crucial.

On the extreme end of the spectrum, if the data logger is monitoring the conditions throughout the transport of a COVID-19 vaccine, a device capable to withstand extremely cold temperatures is needed. A frozen data logger that no longer works isnt' much help.

The rest of this article will discuss the pros and cons of the many types of data loggers.

Why Has USB Been the Dominant Form of Data Logger for Supply Chain Monitoring?

The fact that USB data loggers are inexpensive and small has contributed to their popularity. These loggers only need to be plugged into a computer to provide data transfer from the logger into your network. Most USB loggers can also be configured with built-in alert thresholds for easy release or reject decisions. The logger will show the possible alerts by blinking light or if the device is equipped with a small screen via icons or similar. Unlike some newer technologies like RFID or NFC, you don’t need to build or buy out new infrastructure for USB loggers. You only need to attach the loggers to your shipments. At stops along the supply chain, others can plug the logger into their computer’s USB ports to download the data to their computer. It’s a simple process.

USB loggers are durable enough to work in some challenging environments along the cold chain. They have a 2–3 year battery life. With wireless loggers, the drain of the radio transmissions usually shortens battery life.

The Cons of USB Data Loggers

There are many drawbacks to USB data loggers. Of course, there wouldn’t be so many alternatives if they were perfect. Some drawbacks include:

• You must physically retrieve the logger to transfer data
• They’re a significant cyber-security risk
• There’s no easy way to upload data to a cloud

Whenever you need to retrieve data from a USB logger, you’ll have to go get the logger and plug it into your computer. After plugging it in you need to download the files and to have the records saved you need to manually send the report via email or upload it to a dedicated drive This takes a lot of time and effort. But, the hacking risks are what’s causing some companies to ban USB loggers.

With a USB logger attached to goods traveling through the supply chain, at any point, a disgruntled employee could retrieve the USB data logger. They could plug it into their computer and download viruses, worms, and other types of malicious software on it. The users downstream from where the virus’ entry point to the logger will suffer the effects when they plug the logger into their computer. While this might be an extreme example we’ve seen viruses like the STUXNET automatically targeting connected USB drives and spreading themselves from computer to computer to contaminate extremely high numbers of devices with malicious software.  

Infecting your customers’ computers with viruses is not a good way to maintain business relations. That’s why many companies are switching to other forms of data loggers.

Alternatives to USB Data Loggers

When deciding which data logger to purchase, consider the challenges you’ll face with the products you’re shipping:

1. areIf the data logger will be in extreme cold, you’ll want to know if it can handle the temperatures.
2. How long will the battery last?
3. How much data can you store on the data logger?
4. Will you need to install special readers or wireless networks to use the data loggers?
5. How is it compatible with your current systems?
6. What is your industry’s compliance requirements for data loggers, and how your new possible device can handle those?

These are all important questions to consider when deciding which type of data logger is best for you.

Bluetooth

Bluetooth wireless data loggers have a lot going for them.

They have up to a 100-foot range — sometimes even farther. They don’t require new physical infrastructure, since cell phones can read the data from them.

Like USB data loggers, they’re small, inexpensive, and easy to deploy. The battery life for Bluetooth data loggers is usually around 12 months. It can be shorter if the logger is checking the sensors more often. It can be longer with newer low-power Bluetooth technology. Like most wireless loggers, obstructions such as walls severely limit the range. 

The ease of reading the data with any smartphone means the next warehouse in the supply chain also won’t need special infrastructure to read the data logger. This makes Bluetooth quite scalable. For large volumes, there are also gateways specifically built to read bypassing Bluetooth loggers if the usage of smartphones doesn’t cut it. On the downside, every Bluetooth logger requires a smartphone app to be installed on every device used to read the loggers. Each manufacturer has its own apps which might make it cumbersome to keep up with loggers from different sources. For many large companies, it's also a big effort to get approvals from the IT department to download and install apps on smartphones. 

It’s also good to remember that Bluetooth devices require airline-specific approvals before using the logger in air freight. 

NFC

If you want ultra-secure wireless transmissions, this is your best option. This is the same technology you use for mobile payments in checkout lines. You also don’t have to worry about obstructions with these since you’ll need to read the data logger from within 1.5 inches at most. This is another wireless method that requires virtually no new infrastructure.

While NFC is wireless in terms of not requiring a physical connection between the loggers and the smartphone used to read it, it's still a passive solution with no radio signal emissions. This makes NFC easier for air freight than Bluetooth for example. 

Other than being a passive solution NFC can be easily compared to Bluetooth. Data can be collected with smartphones, but only if the manufacturer-specific mobile application is installed on the phone. The same app installation challenges apply here as with Bluetooth. 

RFID

Radio Frequency Identification (RFID) has been around for a while. Wal-Mart has been trying to get RFID tags on all its products since the early 2000s. After many years of trying, it appears they’re having some success now. But they’re still far from what they originally hoped. 

The applications of RFID are not limited to only identification of the products like with Walmart, but it can be also used to transfer small amounts of data from loggers. 

Wal-Mart wanted to make it where you could pass an RFID reader and it would scan everything in your cart at once. The network would then charge your credit/debit card. Had RFID technology worked as planned, it would have been the end of cashiers and checkout lines. 

The problem is that physics doesn’t allow so many identifiable radio waves from so many items in such proximity. Still, RFID is workable when used to track shipment boxes and crates. But to be more useful than other technologies, you must install an extensive network of RFID readers in the warehouse. Or you’ll need RFID gateways to scan all shipments moving in or out of the warehouse.

To solve this issue of heavy infrastructure requirements some manufacturers are including both NFC and RFID support in their data loggers.

E-Ink Dynamic QR Code Data Loggers

This is a competitor to all the technologies mentioned above. QR code solves issues like misreads related to obstructions with wireless radio transmissions. It’s ultra-secure, like NFC, but you don’t have to be within 1.5 inches of it. You can read it from several feet away just as you do with any QR code with the camera of your smartphone. 

These QR codes are on an e-ink surface similar to ebook readers like Amazon Kindle. The QR code will change based on the data stored on the data logger. When your phone reads the QR code, it is getting the data from the logger. Then, your phone transmits the data to the cloud where it’s available for you.

The biggest benefit of QR code-based loggers is that they truly do not require any infrastructure. While NFC and even Bluetooth can be used with a smartphone those always require a specific app to be installed. QR code-based loggers can be read and the data uploaded securely to the cloud with just the standard camera application of your smartphone. This makes it possible to really know that the recipient of the shipment always has everything they need to check the status of the shipment and upload the recording to the cloud for you.

A group of active loggers: Cellular/Satellite/NB-IOT/LoRa/Sigfox

There are a lot of real-time connected loggers these days. With these active solutions, you are able to get notifications such as temperature deviation alerts already during transportation. Most of these also include a GPS location in their mix of sensors so it’s possible to track the shipments in real-time as well. 

As there are many technologies used to achieve online connectivity the availability of the networks varies as well. Satellite is the most expensive, but also the most reliable solution while cellular devices are still the majority. Cellular solutions are cheaper than satellite-based but still require a data subscription which can be expensive especially when the devices are used internationally. Both of these solutions are also heavy for the battery and usually allow only a 30-90 days battery life.

Newer wireless connection methods specifically built for low-power devices and smaller amounts of data are often generally called IoT networks. In this category we have Sigfox, LoRa and NB-IoT being used to transmit the data to a cloud. These solutions allow much longer battery lives and cheaper data subscriptions, but the availability of the networks really varies. 

What applies to all of the active devices is the requirement of airline-specific approvals. This might make the usage a bit cumbersome at times, but on the plus side, the data is fully automatically available in the cloud all the time when the network is available to the device.

Pricewise the active solutions, especially the cellular and satellite solutions are on the expensive side, even before counting in the data subscription costs.

Conclusion

Will USB data loggers maintain their dominance? Probably not. Many companies fear the cybersecurity risks with USB data loggers. And too many new technologies have surpassed the capabilities of USB data loggers.

Logmore provides what we believe is the best replacement for USB data loggers: E-Ink Dynamic QR Code data loggers. Like USB loggers, you don’t need additional infrastructure. They’re small, inexpensive, and easy to deploy. They’re extremely durable. These loggers avoid the security issues inherent in USB loggers while allowing you to scan the data at a distance like the wireless options.

QR Code data loggers aren’t the most technologically advanced choice available. But this low technology innovation may be the best fit solution everyone is looking for in a data logger. Contact us today for a demonstration of our products. We look forward to providing you with the best data logger experience on the market.   

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