Instrumentation Monthly Test | Measurement | Control
Remember when TVs were operated using analogue? Remember the vast difference it made when your television went over to digital – reception details like the picture quality, number of channels and less programme interruptions?
In the same way the movement from analogue to digital in the world of television has delivered immense benefits, industrial instrumentation has had its fair share of the same. Ease of communication and set up are just two. Others include familiar graphical displays which make it easier for users to operate their devices.
In this article, ABB’s Alan Hunt, Electromagnetic Flow Product Manager, explains the impact of digitalisation on industrial measurement.
Digital communications vs Traditional communications
Digital communications have overcome the traditional issues caused with analogue transmission signals regarding scaling – the mismatch between the transmitting range of an instrument and the input scaling range of the receiving instrument. Incorrect readings would cause operators to waste time looking for phantom measurements that could not be accounted for.
Digital values eliminate this problem. By sending zeroes and ones from A to B, the displayed value will always be a faithful representation of what’s happening in the process being measured.
Another advantage of digital protocols is that you can combine multiple different values into the signal – with traditional analogue only one signal could be sent at one time.
Data is king
Digital communications also enable operators to access rich diagnostics data which indicates whether an instrument needs servicing or not. An example is ABB’s AquaMaster 3 with WITS DNP3, which enables remote access to diagnostics and configuration changes. Any problems are automatically notified to an engineer, together with the time the issue occurred and the exact location of the affected device. This ensures engineers are only deployed when necessary, helping to save both time and money.
Have HART, you’re halfway there
Most instruments make a measurement, amplify it, convert it and then transmit it. In the past, there were possibilities of errors being introduced at each stage. Digital technology means that the measurement is converted into a digital signal as quickly as possible so that the possibility of errors creeping in is reduced.
Unable to completely upgrade your system to digital? It may be that your instruments include HART (Highway Addressable Remote Transducer). HART represents an ideal halfway house for organisations that would like to get more from their instruments without completely upgrading to a digital system. It works by superimposing a digital signal onto an analogue signal, which still relies on an analogue measurement.
Getting on the bus
Everyone has benefitted from the transition from electronic to microelectronic. In terms of bus-based systems, most top end industries have used or are using bus systems in some way.
The problem with bus-based protocols is their complexity. Making just one mistake anywhere when setting up a digital system could mean it won’t work.
A solution to this problem comes in the form of communication. Some engineers may be familiar with writing programs for PLCs but they won’t be familiar with instrumentation. Likewise, a lot of people who work with instruments are not familiar with PLCs. If these two distinct skillsets can communicate about their requirements, then companies can further explore the possibilities that digital technology can offer.
Living the future today
To predict future industrial technology, we should keep an eye on our private lives as it is likely it will follow suit, subject to careful analysis of the security implications.
In ABB’s own range of products, such developments are already apparent in products such as the AquaMaster4 with features such as Near Field Communications (NFC) technology which allows users to access their flowmeter remotely to obtain data and make configuration changes. The use of smart portable devices for instrument configuration makes setting up hard devices in the field faster, simpler and less costly.
With the inclusion of simplified Human Machine Interface, usability is improved, helping to make training and maintenance quicker. In addition, some instruments include Windows interface technology, making it easy to scroll through menus, change settings and navigate between data views.
Summary
Ultimately, digital technology is steadily helping to make life easier – so easy in fact that finding out more about the possibilities for accurate and reliable industrial measurement is as easy as just visiting.