Page 13 - Food&Drink Business Magazine July-August 2020
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 when using a PC, laptop, smartphone or tablet. In addition, sensor access via bluetooth is only possible with an access code. Wireless technology can also be applied to older devices already in the field, as far back as 2002.
Bluetooth offers a form of communication that runs via a separate, second data channel, which makes it function independently of the user channel. In this way, field devices can be analysed in parallel to the existing
process control without interfering with plant security and availability.
VEGA’s PLICSCOM system is also an economical solution when existing systems, which usually only have analogue
4 ... 20 mA interfaces need to be upgraded to digital, in a step by step sustainable fashion.
Importantly, it meets the NAMUR requirements for open architecture, Kaspar says. “The association demands IT components be quickly and flexibly integrated since these are generally shorter-lived than industrial process plants themselves. It is the only way for process engineering to keep pace with the 4.0 development.”
In the future, this local type of bluetooth communication will be expandable to a complete diagnostic network, allowing diagnostic access from the control room down to the field level possible, also for existing analogue field devices from VEGA.
Plant operators will then be able to react faster and in a more targeted manner to errors and detect deviations in the process early by recording the extensive information available in the field device and taking appropriate countermeasures.
It is anything but easy to network field devices via digital fieldbuses, such as Profibus PA or Foundation
Fieldbus, and to make the analysis and evaluation data available to the control level.
Due to their high complexity and costs, these technologies have not yet been able to replace the analogue 4 ... 20 mA process signal as the most widely used interface for level and pressure measurement technology, even decades after their introduction.
Bluetooth has become a bridge technology that points in the right direction. It mediates between the analogue current interface of a field device and the ethernet-based IT networks that are standard in almost all companies today.
But why are field devices in the process industry not upgraded for direct connection to the existing IT infrastructure, through an ethernet interface, for example?
The existing two-wire technology, based on the
4 ... 20 mA interface, has a decisive advantage: measured value and supply voltage can be provided simultaneously via only two wires.
In addition, they belong to the ignition protection class “intrinsically safe”, so they are also ex-proof for use in flammable hazardous areas.
An alternative is the new Advanced Physical Layer (APL) standard. Based on industrial ethernet technology, this intrinsically safe, two-wire ethernet communication will be able to solve demanding applications in process automation in the future.
According to the plan, it will be designed for a range of up to 200 m and a bandwidth of
10 Mbit/s – including the power supply.
Eleven well-known industry partners are currently involved under the umbrella of the Profibus user organisation, including VEGA, as well as the organisations FieldComm and ODVA. Their common goal is to eliminate the communication bottleneck between field devices and the control level.
VEGA’s Inventory System provides a clear and constant stock overview.
 “ These are future-oriented, scalable solutions that can be integrated into existing systems or new ones with a tailor-made basic security configuration...”
Even if several years elapse before the first APL devices are available on the market – if it is possible to radically simplify the setup and administration of such networks – this technology has the potential to become the future standard for process automation.
On the road to Industry 4.0, the focus is on added value for people, applications and enterprises. Kaspar points out that every sensor contains important measurement data for this purpose: “It’s all about getting the most out of them”.
The best networking of data and its users looks different in every industrial process. Wherever encrypted data
transmission via wireless network is a perfect fit for an application, or using VEGA Inventory System, perhaps eventually even APL will take over this task.
The requirements on communication are fundamentally different in each case, but all have the
goal of not leaving valuable sensor data unused in the field any longer.
From configuration to measurement, recording and diagnosis, through to fault analysis, the aim is to make important information transparent and use it to bring the digital interface between automation networks and conventional IT networks a big step forward. ✷ | July/August 2020 | Food&Drink business | 13

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