Boost operational efficiency with remote data monitoring
02 September 2010
Remote wireless based data acquisition is becoming popular for large plants, and plant operators are increasingly favouring the technology over traditional manual data logging activities and hard-wired installations. Derek Moore reports
Economic challenges remains for the UK and with a new government now in power and making its mark, there looks set to be some uncertainty for some time to come. With this in mind, the most important thing for decision makers within processing and manufacturing plants is not investing money, but saving money wherever possible.
However, it can be a false economy to rule out the installation of new plant equipment altogether. Indeed, by investing in new equipment, cost savings may actually be made, particularly as issues such as operational efficiency and energy savings are tackled and resolved by investing in appropriate equipment.
While the installation of new equipment does represent an initial expense, it is possible to achieve a relatively short payback. And after that the equipment will continue to provide operational benefits – and thus cost savings – for a long time to come, making that initial investment all the more worthwhile.
The importance of data acquisition
The reasons for data logging are wide ranging, depending on the application. For example, the quantity of a stored chemical may need constant monitoring, particularly if it is an essential feedstock into a continuous production process. Data monitoring is also an essential element in asset management to ensure that plant equipment continues to function safely and reliably.
Traditionally, the mechanical paper chart data recorder has been a stalwart of the data acquisition infrastructure, providing an analogue real time graphical indication and historical archive of plant parameters. These have often been located at strategic points throughout the plant, connected directly to the equipment they are set up to monitor.
An operator would need to make his or her way around the plant to check these recorders at regular intervals to ensure that all is functioning as it should or, if a problem is spotted, that it is rectified as soon as possible. These time-honoured recorders have served the industry well for many years, but the advent of wireless technology has opened up a new wave of possibilities for monitoring.
Using different types of remote monitoring technology such as GSM, GPRS, Ethernet and Modbus, wireless data recorders can be attached to instrumentation in the same way that traditional recorders were. But that’s where the similarities end; whereas with traditional recorders an operator physically needed to go to the equipment to read the information (if not hard-wired back to a central control room), wireless data recorders offer instantaneous remote access.
Data collected and stored by the recorder is sent to a computer or mobile communication device, so the plant operator no longer has to make what can be a lengthy trip to the other side of the plant. Instead, information is accessed from the comfort of an office or, indeed, from anywhere in the world via a mobile phone or laptop.
These operational efficiencies are advantageous in their own right, but there are further benefits to be gained. The technology also enables alerts to be sent directly to the operator via his or her desktop or mobile device. For example, should an emergency arise, an alarm can be sent wirelessly to a designated device to alert appropriate personnel instantaneously to the problem. In an emergency this is clearly beneficial; for plants that use traditional data monitoring systems, our peripatetic operator may have already left the area before the problem arose and would not be aware of it until he returned to that section of the plant at a later time in his data gathering routine.
Remote wireless data logging offers further benefits in terms of energy monitoring. As data can be gathered at a far greater frequency that is possible with an operator in a van with a clipboard, instantaneous energy consumption can be measured accurately and controlled as necessary. Such real time information can be sent wirelessly to a PC and the data analysed to ascertain if the plant is operating at its optimum energy efficiency or, if it is not, where energy savings can be made.
With times difficult for UK manufacturers at the moment, it can be easy to assume that not investing money in new equipment is the best way forward. However, with items such as wireless-enabled data recorders freeing up staff time to undertake other duties, allowing closer monitoring of key cost areas such as energy and enabling more instantaneous responses to problems, the question should really be ‘can you afford not to invest in this new equipment?’
Derek Moore is with Siemens Industry Automation and Drive Technologies
Wireless data monitoring – a case study
A manufacturer of polymer-based products has 12, 15m high resin silos that feed injection moulding machines. The stock levels in these silos must be maintained at all times in order to meet production demands. Traditionally, staff were deployed to visually monitor the levels of resin within the silos and contact the supplier when they determined that a refill was necessary.
This approach was less than satisfactory as the resin stocks were being kept unnecessarily high as a precaution. Additionally there were frequent and costly emergency deliveries in order to make sure that stocks remained at this high level. And on rare occasions, when resin did run out, production ceased with all the attendant cost implications.
The company decided to install a level measurement system, and chose Siemens Echomax XPS-30 transducers and Sitrans LU long-range non-contacting ultrasonic controllers, an installation that provides continuous level measurements within each silo.
These level measurement systems are connected to Siemens Sitrans RD500 remote data managers, which log the resin levels and transfer this information via GSM/GPRS to a designated computer, laptop or mobile communication device. The RD500 is also able to send messages alerting the plant operator if there is an issue relating to any particular silo.
This installation has considerably simplified resin level monitoring and provides peace of mind that the silos have an appropriate quantity in stock for the current manufacturing requirements. This avoids the costly problems of poor inventory control and unscheduled downtime, and removes the need for a member of staff to manually check the levels. Not only has this reduced inaccuracies caused by human error, it has also freed up operators to carry out other essential roles within the plant.
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