BEYOND SCADA CLOUD OR WIRELESS?

Ten years ago, the assumption was that distribution SCADA would extend into the field to connect devices. But SCADA - a narrowband, traditionally wire-line communication network - has limitations from a cost perspective as well as more recently from a security perspective. Traditional SCADA software pricing models are challenging - the IEC 61850 standard has helped to reduce the integration effort that is complicated by the 150+ SCADA protocols in use at utilities today, though it adds overhead to data communication.

Nonetheless, SCADA and MES software remains attractive for companies relying on automated processes.

TAKING SCADA INTO THE CLOUD

The idea of storing or displaying vital real-time data in the cloud has become more commonplace. With tech giants like Apple, Microsoft, and Google pushing forward the cloud computing concept, it seems to be more than just a passing trend.

Recently the focus of cloud computing has started to shift from consumer-based applications to enterprise management systems, with the promise of less overhead, lower prices, quick installation, and easy scalability.

What are the benefits and risks involved? Cloud computing has strengths and weaknesses, so which factors are important to consider when choosing what information to put on the cloud? The cloud is the concept of using large arrays of remote Internet-based servers to store and handle your information. It is like renting a storage unit for items you want to keep around but can’t fit in your garage. Data is saved off-site, on the servers of a third-party hosted cloud service; this information can be accessed by connecting to the cloud server through your Internet connection.

Although the cloud servers don’t belong to your company, they are used as if they did.

While many cloud services are specifically meant as storehouses for data, some cloud-based SCADA systems are offered as a "service” – which is referred to as SaaS (Software as a Service). The entire system and its data are stored and maintained in the cloud with off-site IT support and scalable server space.

Reports, analytics, and configurations are ideal for the cloud. However, information that is vital to safety and control functions - and that which relies on bandwidth availability and reliability - is particularly important to the operation of a manufacturer. Here, it is essential to weigh the risks involved because it can directly affect functionality and productivity on the shop floor.

While most direct-process SCADA system applications are remaining in-house, many sections of manufacturing plants are relocating to the cloud because the benefits outweigh the risks involved: you pay only for what you use; operating expenses are cheaper; space grows according to need; IT costs are outsourced; sharing and accessing data is easy; upgrading is easy.

On the other hand, the three biggest risk factors to consider for cloud-based SCADA system data are security (a major issue for manufacturing companies), performance, and reliability. Of course, large cloud providers such as Microsoft and Amazon spend a good deal of time and money ensuring that information on the cloud is kept secure. Dealing with hackers and spies online is the new reality of security and every company has to protect itself from cyber-attacks of all types. By choosing to put information on the cloud you are routing sensitive data through a public network, which could leave information more exposed to hacker attacks.

To obtain acceptable performance for certain manufacturing applications, high bandwidth networks with low latency may be required. Exterior networks, such as those provided by Isis, may not be able to meet these requirements, which could cause problems on production lines. SCADA projects are no longer about stop-and-start control and tracking statistics - they have to be able to provide "actionable data” - information supplied fast enough to act upon, so losing this functionality for even a few seconds or minutes can wreak havoc.

WEB-BASED SCADA

 Web-based SCADA software is another approach. Installation is on a central server location, and can be accessed anywhere via a client machine to launch a client application. Users pay one flat price for the server licence, and can then launch as many clients as they want or connect as many tags as they need. Not only is the cost for unlimited, web-based software much lower, but it is much faster to install.

WIRELESS IP-BASED NETWORKS

 More recently, wireless IP-based communication networks have attracted attention for automation applications. With their inherent IP-based security mechanisms, ease of deployment, and broadband speeds, wireless communication networks are quickly becoming a leading choice.

ABB recently announced it has acquired Tropos Networks, a 12- year-old startup company based in Sunningdale, California that links up municipal Wi-Fi smart grid networks around the USA.

Its technology is described as a "mesh IP standards compliant communication network” that operates in unlicensed bands. In a mesh networking (topology), each node must not only capture and disseminate its own data, but also serve as a relay for other nodes - that is, it must collaborate to propagate the data in the network.

It has self-healing capability which enables a routing-based network to operate when one node breaks down or a connection goes bad. As a result, the network, which is mostly used in wireless scenarios, is typically quite reliable, as there is often more than one path between a source and a destination in the network.

As a choice for distribution area field networks, Tropos claims that it can achieve above four (4) 9s of reliability (>99.9999% reliability), which is under a minute of total downtime per year.

Tropos has found a small niche in municipal utilities, where it can promise a smart meter or distribution automation radio network that also supports police, fire, ambulance and even city maintenance work vehicles. It is all based on wireless IP (Internet Protocol) broadband, and ABB plans to integrate it into its existing communications offerings for the power distribution sector.

WIRELESS ADAPTERS

 Lafarge Plasterboard can monitor critical field instruments remotely from the plant control room following the introduction of FieldKey wireless adapters from ABB.

The Bristol factory took part in a successful trial of prototype wireless adapters from ABB early last year, and has now followed up with the installation of several commercial FieldKey units. These are used to check the performance of critical instruments, and are moved around the site to monitor any instruments that engineers suspect may be experiencing a problem.

"We would previously have had to physically go to each instrument and pull off the information onto a laptop," says Electrical Technician Matthew Pepper. "Now we can interrogate instruments remotely, which is especially helpful where access is an issue. We're using the adapters to check that there are no system faults on the instruments, check calibrations and make finetuning adjustments." FieldKey adapters are quick and easy to fit to any instruments equipped with 4-20mA HART communications. On the Lafarge site, for example, they are used with equipment from at least three different manufacturers.

The adapters are small and have a rotating antenna, enabling them to be fitted into extremely tight spaces if necessary. They also use energy harvesting, taking power from the 4-20mA loop, so they don't need batteries. With no need for hardwiring to the network, each FieldKey can be installed in under three minutes, eliminating the need for a plant shutdown and any consequent impact on the existing control system.

The FieldKeys transmit the data from the instruments to a Wireless gateway. The wireless gateway has an Ethernet port to allow process recorders such as ABB ScreenMaster SM500F and also asset management systems such as ABB Asset Vision. In the case of Lafarge, the FieldKey adapters are integrated with the company's existing PACTware asset management system.

The ABB FieldKey adds WirelessHART to any 4-20mA HART instrument, providing remote access to new levels of process, maintenance and configuration information. Its small size and just two wires to connect allows quick and easy installation, its default parameters are set to unlock the information held within the target instrument.

Joining a wireless network is simple, connect the FieldKey via a spare cable entry gland then wire it to the loop