Key points
As the requirements for production automation constantly increase, these requirements, combined with short cycle times mean automation solutions must process an increasingly greater number of measuring values ever more rapidly.
Bernd Knoll, International Product Manager of HBM looks at what this means for modern data acquisition systems and further discusses possible solutions with decentralised intelligence, which is increasingly being used within industrial measurement technology.
Since integrating sensors and instruments with components in production lines and test systems is the only way to enable dynamic models to be implemented, a new breed of data acquisition systems (DAQ) have been developed to fulfil the arduous demands placed on industrial data acquisition.
With performance, flexibility, ease of use and integration top of the list, latest models have been designed to undertake measurement data acquisition, subsequent data processing and transmission to a higher level controller, at very high speeds for example, sample rates of up to 19.2 kHz, for all channels. Parallel to this, data acquisition with very high precision, of up to 0.05% accuracy class is also guaranteed through measuring amplifiers with a high resolution of 24 bits.
Communication with the automated environment with modern Data Acquisition Systems
As the number of measurement channels and choice of interfaces depend on the respective task in the application, modern Data Acquisition Systems comprise a basic device that can be variable equipped with plug in cards for flexibility, which is a key factor.
The first slot is reserved for a communication card that enables integration with a higher-level automation system whilst additional slots are also available for amplifiers with 4 channels each and combined input/output cards.
Different modules are also available with measuring amplifiers for strain gauges (SGs), which can be used for analogue inputs and outputs, and for digital outputs, which enables the most frequently required physical quantities to be measured, such as force, torque, pressure, strain and temperature.
All modules are supplied with voltage via the DAQ basic device and communication with a PC or operating unit can be used for configuration or visualisation via fast Ethernet, which enables transmission of all measurement data up to 100 Mbit/s.
In addition, most basic devices are also equipped with a USB interface which can be used, for example, to save configuration to a USB stick for later retrieval. The connection of peripheral units, such as hard drives or barcode scanners, can also be used to save quality data and to include component identifications in this data.
Virtual channels
Measurement technology in industrial applications must seamlessly integrate with the communication protocols of the automation system, and as data volumes and speed requirements continue to grow, Industrial Ethernet has become increasingly popular as a communication protocol in automation technology.
The result of this growth means that simple field buses such as CAN or PROFIBUS have now been replaced with Data Acquisition Systems, which support real-time Ethernet protocols, such as EtherCAT, PROFIBUS or Ethernet/IP, all of which allow very fast transmission of large amounts of data, in real time.
Furthermore, as the measured signals can already be processed internally by the amplifier and evaluated in real time, this means that these Data Acquisition Systems can therefore effectively implement some of the tasks, directly in the amplifier, which would otherwise be taken over by the high-level controller, such as mean value determination, peak value acquisition and other mathematical calculations.
In addition to the measurement channels offered by the latest range of Data Acquisition Systems, users can also benefit from the systems so-called virtual calculation.
Featuring powerful signal processors, specifically designed for this purpose, which can perform calculations at the required speed, all measured values and the derived values calculated in the virtual calculation channels can be transmitted in real time, with up to 10 kHz to the machine and system controller.
Decentralised, intelligent measurement technology is also another important feature which needs to be taken into consideration. Particularly important for applications with a very high degree of automation, in order to reduce failure frequency and the system load on the controller, typical applications for such decentralised measurement systems can be found in production applications, such as the monitoring of presses, such as tablet and powder presses through to sheet metal presses, commonly used in the automotive industry.
At this stage it is also worth mentioning the importance of frequently monitoring machine parameters in large and complex machines and systems in order to minimise standstill times. By implementing a system, machine errors can be quickly detected, minimising unplanned and costly downtime.
Another classic application case for measurement systems, such as the PMX from HBM, is the industrial test bench set up, where complex components are tested for their maximum loading capacity and practicality. Over the last few years, Industrial Ethernet has become prevalent as a communication medium in this sector.
Equally as important, the same applies for checking the quality of finished products at end-of-line test benches. Storing the quality data acquired here in a database also poses increased requirements for the communication architecture of the measured technology systems.
Incorporating high measurement accuracy and long term stability, the PMX data acquisition and control system from HBM is suited for use in production lines and industrial test benches and enables professional and precise application of force, torque, vibration, pressure, strain, temperature, voltage, current, frequency, speed, angle of rotation, rotational direction and many other quantities.
Visualising and operating concepts
Moving with the times, when it comes to new browser technology, users and system operators are familiar with smart devices and use them on a daily basis. In line with this, modern Data Acquisition Systems incorporate the latest measurement test and measurement technology which offers convenience and ease of use.
Standardised interfaces also provide convenient access to all device parameters for configuration, operation and analysis, via any internet compatible terminal device, meaning users can comprehensively implement applications on mobile devices and cloud solutions in line with Industry 4.0.
Practical answers at your fingertips
Offering a plethora of opportunities, potential applications range from simply utilising a smart phone or tablet as a mobile display for a measuring device, through to controlling networked test benches in a company network, and even monitoring remote wind turbines via the internet.
In addition to simply visualising data, modern technology now allows customers to conveniently and quickly employ control elements, such as buttons and switches for operator actions, such as start, stop or trigger.
Conclusion
High sampling rates, rapid data transmission and integrated intelligence (DSP digital signal processors and CPU) for relieving the higher level automation solution are all significant requirements, which need to be met by measurement technology systems used in the modern industrial environment.
Furthermore, communication via real-time Industrial Ethernet protocols with high data transmission volumes plays an increasingly greater role. Modern data acquisition systems take these considerations on board and have opened the door to a wide range of industrial measurement tasks in product development and testing.
