Internet and wireless technologies are present in our daily life but they are still in the early adopter phase in the tank and terminal management industry. Bertram Kuld of Endress+Hauser explores how new communication technologies are changing terminal operation.
Since ever people communicate to exchange information. For centuries there have been no real changes in the technologies applied – letters or face to face. But in the last decades the communication ways changed dramatically. Electrical signals took over from pen and paper. Via telegrams, telephone, fax the era of internet was entered. In recent years there was another push coming from the mobile technologies. Now the internet is everywhere and every time available. A study, done by Ericsson AB (Sept. 2010), shows that with cable based internet 1 billion places would be reached by 2020. With the mobile technology the number of connected people increases to 5 billion. The International Telecommunication Union (ITU) estimates that 35% of the world population has access to the internet – doubled the number within 5 years. The latest trend is the extension of “internet users” from people to machines bringing the number of connections to 50 Billion by 2020 (according Ericsson AB, Sept. 2010).
When Sir Tim Berners-Lee employed at CERN, Geneva, wrote the first web browser and web server in 1989 it was all about the easier exchange of information by scientists. Nobody thought of a mass usage that time. But the ease of the technology was overwhelming and was the origin of a new era. Today Internet is everywhere and much more than an information gathering and exchange mechanism: Shopping, banking or meeting with friends is done online.
The cost impact
Another reason for the success of the internet and its web technology is that it comes for with little costs and is always up to date. Once a PC with a browser is bought surfing the internet is possible and for most of the functionality it is for free – beside the monthly fee on the telephone bill of course. If the content of a web page is updated it is still possible to view the data with the existing browser. In case the PC is updated and a new browser is installed the web pages can still be viewed. Changes in operating systems do not affect the display of the web pages whereas for installed PC software a change in operating system often means an update for this software as well. Especially companies face a high cost impact in this field. Analysts estimated that on every dollar spent there are another five spent for technical consultancy.
Webserver in the process industry
In the process industry the control room is the heart of operation of the plant. Here all information from the field comes together. Traditionally the control room combined the units for acquiring the data from the field instruments and represented the data on dials or a pen recorder. Today most of the time separate server rooms are established hosting the data acquisition units and the servers. In the control room client stations receiving data from the server are installed and the information is presented with intensive usage of graphics for visual representation. In some cases the intensive usage can lead to an information overflow.
The next step would be to change servers to web servers and having only PC with browsers in the control room. A good example for a system offering this possibility today is the Tank Gauging System Tankvision by Endress+Hauser. In this system the data acquisition unit has a built-in web server allowing the access to the information from any browser connected to the local area network (LAN). In case the LAN is part of a company intranet the headquarters would for example have the possibility to view the data of the sites connected. And the data is secure as IT departments use all mechanism like firewalls to protect the internal systems.
As mentioned above the wireless technology accelerated the usage of internet extensively. At home, in the café or in the office wireless LAN (WLAN) is available today and every data exchange running on the LAN is also available on the WLAN. Therefore from the field data acquisition unit upward this technology can be fully applied.
Communication into the field
It would be consequent to extend the WLAN into the field to have the same technologies throughout the company from the field device to the enterprise resource planning system. But the technology needs more energy than some field devices are capable to deliver in particular intrinsic safe devices installed in hazardous areas.
Therefore technologies like wirelessHART start establishing themselves in the industry. Due to the limited available power the distances are relatively small. To overcome this wirelessHART uses the MESH technology. This means that every transmitter acts as well as replicator for the data of the device more distant from the receiver. The availability of the system is increased by the MESH technology. In case a unit is not available on the direct way of the data from the transmitter to the receiver, the data will find its way via another unit.
Nevertheless especially in tank gauging where longer transmission ranges matter to cope with the distances, MODBUS wireless is used. Distances of more than one kilometer are possible and it also applies the MESH technology for higher availability. Furthermore remote configuration of the field devices is possible via MODBUS wireless and it can be connected with already existing wired MODBUS. Important in particular for tank gauging is the area of custody transfer: With MODBUS wireless custody transfer systems are type approved (according PTB).
The needs addressed
Several problems can occur when running a business. In sales there is a lack of information on customer demand and available sales stock limiting customer retention and service level. Production planning is missing sales forecast and customer demand information and is therefore increasing required safety stock. Lack of information about equipment health increases maintenance cost is an issue for the maintenance personnel. The controlling department is lacking accurate and on time stock and transaction information which might result in operational costs increase and bears the risk of unaccounted material losses. Logistics is missing planning information resulting in increased logistic cost. The reason for the poor information flow is the usage of different system in every of the above mentioned departments. Still a lot of the exchange is done by print outs which can be outdated at the time they are printed.
Web and mobile technology can help to overcome those issues by providing direct machine to machine (M2M) interfaces or easier online data distribution. Taking the sales person as example, when he is with his customer, he could look up the exact available stock by using the web browser on his smart phone. Another example would be online co-operation. As the systems are connected via LAN it would be easy for the maintenance person to bring in an expert from the supplier in with a remote access to solve the issue.
Making more out of the available data
Another possibility to use the obtained data is to condition them to key performance indicators (KPI). These KPIs and the representation in dashboards bring the performance for core values of the business or business unit to light. For example a KPI for a terminal could be how often the content of a tank is changed over. The KPI can easily be presented in a form of a traffic light or dial making the situation obvious and giving the signal to change or even further enhance the situation.