Accelerate into the future of IO-Link Sensors

The new integrated amplifier module offers numerous features that significantly improve the quality of your force measurement: 
 

• Linearisation functions
• Two limit value switches
• Freely adjustable low-pass filters (Bessel and Butterworth)
• A single fixed digital output (DO); an additional digital output is optional in standard input/output (SIO) mode
• Sensor health monitoring: warning in the event of critical operating states. (static and dynamic overloads, temperatures outside the specification)
• Statistical functions (min/max memory, average values, number of measuring points, etc.)

Linearisation functions

You can linearise using interpolation points or cubic linearisation functions. The programming is done in such a way that results from standardised calibration certificates (ISO 376, DKDR3-3) can be entered very easily. Of course, you can also perform linearisation using your own reference measurement. It is possible to work with reference points for this purpose. 

Freely adjustable low-pass filters (Bessel and Butterworth)

The cut-off frequency of the filters can be entered easily by typing the cut-off frequency as a numerical value into the software. These are sixth-order digital filters.

Two limit value switches

The limit value switches are programmed according to the specifications of the IO-Link Smart Sensor Profile. In addition to the threshold value, you can define a hysteresis if your process requires this. The so-called ‘window mode’ is also available. Here, a limit value switch is activated when the measured value is within a range defined by you, for example, between 1 kN and 1.8 kN.

Both switches can be negated.

One fixed digital switching output, one switchable switching output

A single IO-Link digital output is always available so that results can be obtained quickly at the digital switching output. The output switches at a maximum of 0.35 ms going high after a threshold value is exceeded or low if the threshold is undershot. You can deactivate the transmission of the IO-Link communication and use the line that becomes available as a second digital output (SIO Mode). The force transducer then becomes a force switch with two switching points.

Sensor health monitoring: warning in the event of critical operating states (static and dynamic overloads, temperatures outside the specification)

During production, all essential sensor properties are stored in the amplifier:

• Highest operating temperature/lowest operating temperature
• Limit temperature electronics
• Processor limit temperature
• Highest nominal force/lowest nominal force
• Maximum operating force/minimum operating force
• Highest nominal temperature/lowest nominal temperature
• Maximum peak – peak value (amplitude)

The electronics constantly compare the force and temperature values with the limits and report any overruns so that appropriate action can be taken.

Statistical functions (min/max memory, average values, number of measuring points)

All statistical functions are determined at a measuring rate of 40 kS/s. This is particularly useful for the min/max values. 

Our IO-Link sensors work at a high measuring rate and support the fast IO-Link COM3 standard. 

HBK utilises the COM3 transmission rate and, therefore, the fastest possible data rate in the IO-Link world. Internally, the amplifier module operates at 40 kS/s, so that even highly dynamic signals are stored correctly in the peak value memories.

This question has two aspects.

Firstly, the signal runtime in the HBK electronics has a maximum duration of 350 µs. This means that it takes 0.35 ms for a physical event (a signal change) at the input of the amplifier to be available at the output of the amplifier module.

To determine the maximum signal propagation time, the cycle time specified by the master is an important parameter. If we assume that the master works with a cycle time of 2 ms, the maximum latency time would be 2.35 ms until the signal is available to be processed in the IO-Link master.

The output at the digital switching outputs is only determined by the latency of the amplifier module: here, the runtime is 0.35 ms. Please note that filters extend the signal runtime.

Secondly, the bandwidth of the measurement chain depends on the stiffness of the sensor, the installation conditions (coupled masses, stiffness of the force inputs) and the number of measured values/time unit. The amplifier module is able to realise a cycle time of less than 1 ms. This means that 1 kS/s can be transmitted. A rule of thumb says that the bandwidth of the measurement corresponds to about 1/10 of the measurement rate, so a bandwidth of 100 Hz is feasible. The cycle time is specified by the IO-Link master.

The bandwidth, which is decisive for the maximum and minimum value memory, is significantly higher. The module has an internal sampling rate of 40 kHz. This corresponds with an internal bandwidth of 4 kHz.

The IO-Link interface can be integrated into all common fieldbus architectures and makes commissioning very easy!

An IO-Link master serves as a node to which the individual IO-Link sensors are connected in a point-to-point connection. IO-Link masters serve as gateway modules for integration into the automation level. IO-Link masters are available for all fieldbus and industrial Ethernet protocols. This means that HBK force transducers, load cells and torque transducers, along with many other sensors or actuators, can now also be connected easily and efficiently with the IO-Link interface into customers' control system architectures.

IO-Link uses an inexpensive, unshielded cable to ensure reliable and interference-free data transmission (at 24 V) and power supply. This very flexible cable has no mechanical influence on the measurement, even when very small loads are involved.  As there is no shielding, the housings of the HBK IO-Link sensors and the IO-Link master are galvanically isolated from each other.

Yes, the same services are available for the new generation of digital IO-Link force and torque sensors in the accredited HBK laboratory as for the analogue sensors. The traceability of measurement equipment required by ISO 9001 is therefore guaranteed.

HBK has a calibration laboratory accredited in accordance with ISO 17025. Calibration at HBK meets the requirements of the relevant quality standards, including ISO 9001. Digital sensors are calibrated on the same equipment that is used for analogue sensors. This means that customers who have opted for IO-Link as an interface benefit from the exceptionally high accuracy of HBK force and torque calibration machines.

The calibration procedure is slightly different.

In the initial stage, the sensor's stored linearisation data is read out and saved. This applies to the stored coefficients of a compensation function as well as any interpolation points that may have been entered.

Following that, all linearisation coefficients or interpolation points are deleted and the linearisation function is switched off. The amplifier now works linearly.

Finally, the sensor runs through a force or torque series, and the linearisation coefficients are determined and entered into the sensor.

Calibration is carried out according to the standard, according to customer requirements, and in accordance with ISO 376 or DKDR3-3 for force, or DIN 51309 and VDI/VDE 2646 for torque. Factory calibration certificates are also available.

The sensor is delivered as a linearised measurement chain. The calibration certificate specifies the measurement uncertainty of the overall system. The original characteristic curve is calculated from the stored coefficients so that the entire history of the sensor is available to you.

Cost savings, simple set-up and communication right down to field level. Increased operational reliability – the IO-Link advantages speak for themselves! 

The cost advantage is one of the greatest benefits. IO-Link technology offers cost savings by eliminating the need for an amplifier in the control cabinet. Additionally, cabling expenses are significantly reduced due to standard IO-Link cables. Furthermore, the time-consuming process of parameterising the conventional measurement chain is eliminated. With IO-Link sensors, measured values are directly output in the appropriate physical units (N, kg, Nm, etc.) without the need for time-consuming parameterisation.

Additional IO-Link benefits result from improved operational reliability: digital signal transmission is less sensitive than previous analogue technologies, and the sensor continuously monitors applied loads and temperatures, issuing warnings before any damage occurs.

Of course, it is very helpful to be able to communicate from the control level to the interface to the process - the sensor.

HBK IO-Link sensors with an IO-Link interface achieve very high precision for industrial use.

As the sensors have an integrated linearisation functionality the characteristic curve errors can be reduced and are therefore smaller. With IO-Link force sensors, for example, the tension/compression characteristic value difference can be corrected, which results in a higher accuracy.

The IO-Link amplifier module has a low signal/noise ratio and the digital signal transmission prevents cable influences. All in all, these smart industrial sensors gain accuracy in standard industrial applications.

No, leveraging the IO-Link interface, HBK is able to integrate intelligent process algorithms into mechanical quantity measuring sensors like force, load and torque sensors. This enables standardised commissioning for customers, ensuring ease and efficiency.

IO-Link technology has its origins in the field of switching sensors and, over the last few years, has established itself as the industry standard for digital sensors. In more recent years, measurement sensors and control elements such as actuators have also been increasingly equipped with IO-Link technology. Based on high-performance microelectronics, it is now possible to integrate HBK's domain-specific algorithms directly into sensor electronics:

• Filters (Bessel, Butterworth, multi-stage filter cascades)
• Linearisation functions (table, polynomial)
• Compensation algorithms
• Sensor health monitoring (tracking mechanical influencing variables on the sensor)
• Process algorithms (filler, checkweigher, min/max, limit switches, power calculations for torque sensors and more)

This enables the sensor to operate with extensive measurement data pre-processing and process control capabilities. The IO-Link interface now serves as a communication interface to transmit these pre-calculated results, the added value of information (alarms, events) and the measurement value data with a cost-effective and universally applicable interface technology. IO-Link is the perfect communication interface for smart sensors in the field of physical and mechanical quantities such as force, weight and torque.

The new amplifier module offers numerous features and functions that significantly improve the efficiency and performance of your weighing applications:

• Two-point scaling or in process adjustment (calibration process/teach-in)
• Two limit value switches
• Up to five filter stages can be cascaded: FIR, IIR and comb filter as well as moving average
• Process algorithms: integrated filler and checkweighing algorithm                                         
• One fixed digital switching output, one optional switching output
• Sensor health monitoring: warning in the event of critical operating states (static and dynamic overloads, temperatures outside the specification)
• Statistical functions (maximum, minimum, peak-to-peak)

Two-point scaling and calibration assistant

You can store a two-point scaling by entering it manually. There is also a calibration/teach-in assistant that can be used to calibrate using reference weights.

Filters for weighing applications

It is possible to use up to five filters in a filter cascade. In the initial stage, FIR and IIR filters can be set in order to obtain the transient response and a stable measurement signal. To filter out unwanted periodic interference frequencies, up to four stages of comb filters and/or moving average filters can also be added.

Two limit value switches

The limit value switches are programmed according to the specifications of the IO-Link Smart Sensor Profile. In addition to the threshold value, you can define a hysteresis if your process requires this. The so-called 'window mode' is also available. Here, a limit switch is activated when the measured value is within a range defined by you, for example between 1 kg and 1.8 kg.

Both switches can be negated.

Application-specific process algorithms

HBK IO-Link load cells offer integrated checkweighing and filling algorithms.

The filler algorithm allows for process control of simple and complex filling processes. The algorithm optimises and controls the coarse flow and fine flow timings as well as fine flow lockout time and the residual flow time. With this algorithm the IO-Link load cell functions as decentralised process controller, realising efficient and highly optimised filler applications.

The checkweighing algorithm allows for optimised and fast measurements of all common industrial checkweighing applications. Pre-Triggering and Post-Triggering can be set and externally communicated to the load cell via IO-Link. Paired with an optimised filter setting, fast and highly accurate measurements are possible.

One fixed digital switching output, one configurable switching output

A single digital output is always available so that results can be obtained quickly at the digital switching output.

You can deactivate the transmission of IO-Link communication and activate SIO mode. The line that has become free now functions as a second digital output. Both distributed input/output systems (DIOs) can be used for process control of the integrated filler and checkweigher algorithms and limit switches.

Sensor health monitoring: warning in the event of critical operating states (static and dynamic overloads, temperatures outside the specification)

During production, all essential sensor properties are stored in the amplifier module:

• Highest operating temperature/lowest operating temperature
• Limit temperature electronics
• Processor limit temperatures
• Highest rated load/lowest rated load
• Maximum operating load/minimum operating load
• Highest rated temperature/lowest rated temperature
• Maximum peak-peak value (amplitude)

The electronics constantly compare the load values with the limits and report any overruns so that appropriate action can be taken.