Adding IO-Link Wireless unbound ability to transmit via air, without being confined by cables, makes this transmission smooth and virtually boundless. Even a line of sight is not needed for the enablement of industrial wireless communication.
The industrial world keeps progressing in huge steps, making significant technological leaps, and ever-evolving. These include the realms of Industrial IOT, smart factories, and more. Yet, no major change can be made all at once. A smooth transition relies on a system’s ability to gradually convert and adapt to such changes.
In the case of manufacturing lines, logistic automatic warehouses, and more, legacy machinery makes up a vast part of the facility’s equipment. Attempting to replace a big part of it in a short period of time would lead to downtimes, complications, and great expense.
Since IO-Link Wireless was created with problem solving (and not problem causing) in mind, so were the means for enabling a smooth transition into it – both for new equipment and for retrofitting of existing ones.
Though a key conversion required for this machinery would be IO-Link to IO-Link Wireless, additional conversions would be necessary to ensure the ability to upgrade entire lines and facilities quickly and easily. Such conversions include Digital to IO-Link Wireless and Analog to IO-Link Wireless.
While the conversion of IO-Link to IO-Link Wireless can be done directly with devices such as the TigoBridge A1/B1 and the TigoHub, and the conversion of Digital signals to IO-Link Wireless – with TigoBridge A2/B2 or the TigoHub, analog signals require an additional step.
The conversion of Analog signals to IO-Link Wireless is done in two steps. First, the Analog signal is converted into IO-Link with the TigoConverter; and then from IO-Link to IO-Link Wireless with any of the abovementioned IO-Link Wireless Devices.
Smart Factory Operations and Manufacturing Require High-Quality Data
Transitioning from a single-directional communication method, such as Digital or Analog, to IO-Link’s bi-directional communication allows high-quality transmission of data. Adding IO-Link Wireless’ unbound ability to transmit via air, without being confined by cables, makes this transmission smooth and virtually boundless. Even a line of sight is not needed for the enablement of industrial wireless communication.
Analog Signal to Digital Conversion: How Does It Work?
Prior to deep-diving into Analog to IO-Link Wireless conversion, let’s briefly explore the more traditional Analog to Digital conversion, and discuss why this conversion is no longer sufficient in today’s industrial world.
In not so distant past, manufacturers used analog-to-digital converters to convert analog to digital signals for several reasons:
- Unlike Digital signals, Analog Signals are more prone to noise and signal degradation, compromising the data’s precision and integrity.
- As IT and OT systems speak Digital, incorporating the data in a Digital form is much easier and more accurate. Analog data may require manual handling, which is inefficient and leads to human errors.
- Analog systems are often less flexible and not as scalable as Digital systems, confining their users to a bound setup.
- While Analog systems often require on-site presence to be operated and monitored, Digital systems allow remote access, yielding better workflows and efficiency.
The list of reasons to convert from Analog to Digital goes on, yet it pales in comparison to the benefits of converting from Analog to IO-Link Wireless, which expands these and enables many other advanatages.
Analog signal-to-digital conversion, or Analog-to-Digital Conversion (also known by the abbreviation ADC), consists of sampling, quantization, and encoding:
Sampling
Sampling is where the continuous analog signal is measured at regular intervals to produce discrete values. The sampling rate, measured in Hertz (Hz), must be at least twice the highest frequency in the analog signal to avoid aliasing, per the Nyquist-Shannon theorem.
A sample and hold circuit stabilizes the signal during conversion, ensuring accuracy. Higher sampling rates capture more detail of the original signal, which is essential for data acquisition, and digital communication, as well as applications in audio and video processing. The conversion of these sampled values into digital form enables precise, versatile, and scalable signal processing in advanced digital systems.
Quantization
Quantization is the phase in the Analog-to-Digital Conversion process, where the continuous range of sampled analog signal values is mapped to a finite set of discrete levels. This step involves rounding the sampled values to the nearest predefined levels, determined by the resolution of the ADC, typically measured in bits. For example, an 8-bit ADC has 256 levels, allowing each sampled value to be represented by one of these discrete levels.
The precision of quantization affects the accuracy of the digital representation, with higher resolution providing finer granularity and closer approximation to the original signal. However, it’s important to keep in mind that quantization inherently introduces a small error range, known as quantization noise, which can be minimized but never entirely eliminated. This conversion enables the precise manipulation and analysis of signals in fields such as telecommunications, audio processing, and instrumentation.
Encoding
Encoding is the final step in the ADC process, where quantized values are converted into binary format for digital processing and storage. Each quantized level is assigned a unique binary code, allowing the continuous analog signal to be represented as a series of discrete digital values. The number of bits used in encoding determines the resolution and accuracy of the digital signal, with more bits providing a more accurate representation , the same as in the quantization phase.
This binary representation allows digital systems to process, analyze, and transmit the signal efficiently. This enables applications in digital communication, data storage , and computing while handling signals robustly and accurately.
ADC was the preferred method in the industrial realm for years. However, manufacturers and logistics specialists recently came to realize that Analog to IO-Link (and in that, Analog to IO-Link Wireless) conversion, entails many additional virtues.
Features of Analog/IO-Link Wireless Converters
As mentioned above, the conversion of Analog communication into IO-Link Wireless enabled industrialists to achieve new and advanced capabilities, without the need to replace existing machinery in their lines.
The conversion is done with hardware that connects to the existing Analog sensors for the conversion. This is basically an analog-to-digital converter, specifically converting to IO-Link.
- Analog to IO-Link conversion is done with the TigoConverter – a compact device that connects to a current (4mA to 20mA) or voltage (0-10VDC) source and converts the value to IO-Link. This is an analog-to-digital converter, specifically designed for IO-Link.
- The second step is the conversion of IO-Link into IO-Link Wireless. For this end, an IO-Link Wireless Bridge (TigoBridge) or IO-Link Wireless Hub (TigoHub) connects directly to the Analog Converter, converting the IO-Link signal to IO-Link Wireless. This eventually enables the measurements from the analog sensors to be communicated to the IO-Link Wireless Master (TigoMaster or TigoGateway) over the air.
- Both the Analog to IO-Link, and the IO-Link to IO-Link Wireless devices get their power from the Analog device’s M12 connector, without the need for an additional power supply. In this manner the two separate devices act as one Analog to wireless converter, enabling the capabilities of IO-Link Wireless for Analog devices.
This simplifies deployment and machine retrofit by easily creating an industrial-grade wireless connection for analog devices, such as vibration sensors and load cells. While using two separate devices to convert from Analog to IO-Link and then from IO-Link to IO-Link Wireless might seem excessive, realistically this is a very simple setup. It allows users to remove the Analog to IO-Link converter at other times, if they wish to use it to convert from Digital or IO-Link directly for other sensors and actuators.
Benefits of Analog Sensors to IO-Link Wireless Conversion
Analog sensors have been widely used in factories for various monitoring and control applications, yet they display several disadvantages, especially when not converted into digital signals, such as IO-Link. Here are some of them:
- Signal Degradation Over Distance: Analog signals can degrade over long distances due to electromagnetic interference (EMI), noise, and resistance in the cables. This degradation can lead to inaccurate readings, which can affect the quality of the process or product. It does not occur with digital signals such as IO-Link or IO-Link Wireless.
- Complex Wiring: Analog sensors typically require complex wiring for signal transmission, often involving multiple cables for power, signal, and grounding. This complexity can increase installation costs and the likelihood of wiring errors. IO-Link Wireless offers an alternative, as the analog sensor connects directly to an IO-Link Wireless device, negating the need for complex wiring.
- Noisy Signals: Analog signals are more prone to noise, which can be introduced by various sources, including the sensor itself, the environment, or the transmission line. Noisy signals can lead to unreliable data, requiring additional filtering and processing to obtain accurate information. Converting the signal into IO-Link Wireless retains the signal’s high quality and data integrity.
- Limited Flexibility and Integration: Analog sensors are less flexible when it comes to integrating with advanced digital systems, such as PLCs or IoT platforms. This limitation can hinder the adoption of advanced automation and data analytics technologies in the factory. Converting Analog signals into IO-Link Wireless enables quick and seamless integration with these platforms.
While analog sensors have been a staple in industrial applications for many years, using them in their original form leads to numerous disadvantages. This makes them less suitable for modern factories, especially those aiming to implement advanced automation, data analytics, and IIoT systems. IO-Link Wireless enables mitigating these disadvantages, without the need of replacing the Analog sensors themselves.
How to Use Analog Sensors for IO-Link Wireless
The usage of Analog sensors with the wireless IO-Link extension (a.k.a IO-Link Wireless) system is easy and user-friendly. Essentially users would benefit and act in the exact same manner with these Analog devices as they would have before. The only difference would be with the system setup, as these devices would now act as part of a whole system, and not as individual items.
Configuring the Analog devices as part of the IO-Link Wireless system provides new visibility for these, allowing bi-directional communication and visibility. This also enables industrialists to make knowledge-based decisions on the go, including reconfiguration of devices, even remotely.
Once the analog sensor is connected to the TigoConverter, the latter is to be connected to an IO-Link Wireless Device (TigoBridge or TigoHub). Then, a connection is to be made between the IO-Link Wireless Device and the IO-Link Wireless Master (TigoMaster or TigoGateway). This connection is configured with the help of TigoEngine.
TigoEngine is a software-based engineering tool for the efficient setup of IO-Link Wireless Masters and Devices (including ones converted from IO-Link, Digital, and Analog). It enables the installation, configuration, and monitoring of an IO-Link Wireless system, and within it one or multiple Analog sensors. It also simplifies the deployment and maintenance of the devices, making the conversion from Analog to IO-Link Wireless and from there the implementation within the system seamless and easy.
TigoEngine enables the aggregation and communication of data wirelessly collected throughout the system. This data is gathered from the converted Analog devices, and any other device that is connected to the system, sending it to enterprise and cloud-based applications for further processing for dissection-making abilities.
Frequently Asked Questions about Converting Analog to IO-Link Wireless
What is the difference between Analog and IO-Link?
The difference between Analog and IO-Link is reflected mainly in their methods and functionalities. Analog signals use continuous voltage/current signals to reflect information. They are simple and compatible with basic applications.In contrast, IO-Link is a standardized digital communication protocol that allows bidirectional data exchange, offering robust, noise-immune communication and providing rich data.
What is the alternative to IO-Link?
Alternatives to IO-Link include various fieldbus protocols and wireless communication standards. Yet, these pose disadvantages in comparison to IO-Link such as higher complexity, less flexibility, less intelligence on the device itself, and slower performance.
Can IO-Link do analog?
IO-Link can do Analog, yet in a digital manner, thus an analog signal to digital conversion is required. To be able to use Analog devices (such as Analog sensors) with IO-Link, a converter is required. In the process, a source of current (4mA to 20mA) or voltage (0-10VDC) is converted to an output of the value to IO-Link.
Ofir is an experienced support manager with 23+ years of experience in global tech companies and industrial automation. He possesses strong skills in process control, industrial communication and control systems. As Head of Technical Support, Ofir led teams of technical engineers providing presales, post sales and professional services at Unitronics and Megason.
Ofir holds a BSc. in computer science and electronics & control.
