Opportunities abound in telemetry and automation

Changes and innovations in the world of local and wide area telemetry and automation are providing new opportunities for electrical and communications contractors.

There are opportunities to provide solutions for customers in existing as well as new applications that contractors have traditionally not been able to access. Wireless telemetry and automation product solutions are becoming far more available. They are becoming easier to install and program, and lower costs make them suitable for a far wider range of applications.

Today, it is often far better using wireless devices for lengthy or difficult cable replacement or remote site monitoring and control applications, instead of running miles of conduit or digging the traditional trench.

The availability of off-the-shelf standard wireless products is exposing multiple applications previously deemed either too expensive or not requiring monitoring.

While these new opportunities are real and ongoing, there is also the risk that new contractors in this field apply unsuitable technology that could lead to performance and/or reliability issues. It is important to have a basic understanding of the different technologies and which radio techniques offer the best fit for purpose. This will ensure the best possible chances of a reliable installation.

Contractors new to this field should concentrate on wireless products operating in the free, unlicensed, 900 MHz band frequencies, which are suitable for most industrial applications.

The unlicensed regulations imply responsibilities on the manufacturer, the supplier and the installer to ensure installed equipment has the technology and robustness to co-exist with other nearby systems that are also operating on the same frequency. That means equipment should utilise frequency-hopping techniques. Equipment must also comply with current Australian regulations.

Large existing installations

There are extensive deployments of telemetry and automation technology in the mining, energy, broadcasting, manufacturing, environmental, water and wastewater industries - to name a few.

Twenty years ago, the fixed radio and communications infrastructure used in wide area telemetry for distributed control system (DCS) and SCADA (supervisory control and data acquisition) systems was extremely complex.

It required significant engineering by automation engineers with university degrees and years of practical experience. The equipment was also prohibitively expensive to design, install, commission and maintain.

DCSs that exist in industrial process plants required high-bandwidth, low-latency data networks with everything working in real time.

SCADA’s applications in power distribution, natural gas and water pipelines with sites that are widely separated geographically required low-bandwidth/high-latency links.

The DCS and SCADA systems that tie together decentralised facilities such as power, oil and gas pipelines and water distribution and wastewater collection systems have traditionally used combinations of radio and direct wired connections that feed back to centralised control centres.

Technological advances

The RTUs (remote telemetry units) that are used to send supervisory data back to a SCADA system’s control centre and the PLCs (programmable logic controllers) used to control machinery have grown more and more capable of handling local controls as technology has advanced.

Today, the boundaries between these systems are blurring while telemetry and automation products are also coming down in price dramatically.

The demand for simplicity with reliability is increasing the requirements for ‘plug and play’ operation to the point where new wireless cable replacement technologies allow full programming of modules with just a screwdriver. Complex laptop programming is no longer required.

This means that the technology can be deployed in a far greater range of industries and applications. Electrical and communications contractors, with vendor support, can now set up and install these systems themselves.

Many more types of devices can now be connected easily. The latest wireless telemetry technologies allow users to set up the equivalent of a 64 in/out multicore cable in less time than it takes to bake a cake.

Some battery-powered wireless sensors can operate in excess of five years on a single battery. This opens up applications for easily monitoring levels, alarms, flows and temperatures from plant or equipment many kilometres away.

Users can transmit and receive status data for pumps and motors, turn lights on and off, open and close gates, monitor perimeter security, open and close valves, adjust HVAC systems and measure flow, temperature, pressure and levels.

New installation opportunities

Easy-to-use, plug-and-play, DIN rail-mounted, screwdriver programmable telemetry systems are now the fastest, easiest and most economical method for wirelessly duplicating signal wiring. They can make connecting previously extremely difficult sites as simple as turning a screwdriver.

This opens up new markets and applications where, traditionally, trenching, conduit and control cables were used. Plug-and-play telemetry systems can replace existing hardwired systems or can be used for quickly installing new infrastructure, eliminating costly trenching or the requirement for running conduit. Some contractors are even using this equipment as an emergency backup system when a hardwired system is down for repair or maintenance.

Most new buildings have advanced building automation systems for the control of mechanical, electrical and plumbing systems. Installation opportunities also exist in older buildings. In older factories, buildings and apartments without advanced building automation systems, wireless systems can be retrofitted to control things like HVAC, indoor and outdoor lighting as well as security and fire alarms. Related parameters (eg, temperature) can be sent via wireless telemetry to a central location. The information can be collected and processed, enabling the most efficient use of energy. These systems can also facilitate predictive maintenance.

New installation opportunities exist in many other sectors that would have previously found the technology too expensive, such as agriculture. Telemetry can be used in agricultural water management. Major applications include water level monitoring, tank and trough monitoring, irrigation control and leak detection. Telemetry control allows farmers to intervene with assets such as pumps and allows them to remotely switch pumps on or off depending on the circumstances. No longer is there the need or requirement to physically check the tank level every day. Saving real working hours is now a reality that saves time and money.

Battery-powered wireless sensors

Wireless sensor technologies have significantly evolved in the past few years, giving users across a wide range of industries the ability to create a more efficient and cost-effective way to automate and monitor processes and systems.

The new breed of weatherproof, battery-powered wireless sensors also has integrated wireless transmitters. These sensors can be used for monitoring various conditions including liquid level, pressure, flow and temperature, and triggering setpoint alarms.

These devices are self-contained and battery-powered, eliminating the need for external power or expensive solar systems with the required batteries and charger. This new breed of wireless sensors can operate for many years from a single non-rechargeable lithium battery.

Wireless transmitters can be equipped with local displays for instantly viewing process data as well as using the LCD for configuration. This means no PC, cables or tools are required to program the device.

For electrical and communications contractors, this means that new markets are opening up that were previously controlled by engineering firms.

Contractors can offer installation and support of ‘last mile’ connectivity solutions in any existing wireless SCADA and telemetry application. These opportunities can be found in general industry, power, oil and gas, refining, petrochemical, utilities, broadcasting, water and environmental industries.

Technology choices

Wireless data communication devices typically utilise wireless transceiver modules that operate in the licence-free Industrial Scientific and Medical (ISM) radio frequency bandwidths of 900 MHz and 2.4 GHz.

Wireless transceiver modules operating in the 900 MHz bandwidth offer up to twice the transmission range and penetrate obstacles (ie, walls, buildings, trees, etc) better than 2.4 GHz transceivers. 2.4 GHz transceivers, however, offer higher data rates.

900 MHz frequency hopping wireless modules can offer extremely good performance in industrial applications - ‘noisy’ areas can co-exist with other systems on the same frequency band (915-928 MHz).

While 900 MHz signals outperform 2.4 GHz signals, the 900 MHz band is only available in North America, South America, Australia, New Zealand and Israel. Wireless transceivers operating only in the 2.4 GHz band are allowed for licence-free communications throughout most of the rest of the world.

Spread spectrum communications by design carry the added benefit of interference immunity. This occurs due to noise resistance capabilities (as in direct sequence spread spectrum - DSSS) or the frequent changes in the hopping sequence as the signal is moved throughout different frequencies (as in frequency hopping spread spectrum - FHSS).

Some wireless transceiver modules offer additional interference rejection, or blocking, achieved with proprietary filtering and communication across a narrower band of hopping frequencies.

Regardless of the technology used, it is wise to always configure the system and test functionality on the bench before any installation in the field. That way, if there is a problem, you will know quickly whether it is site related to communications.

Wireless cable replacement installation for many applications is in easy reach of many electrical and communications contractors. By using the latest ‘plug and play’ technologies, successful installations can be set up and operating in a fraction of the time it would take to dig trenches and lay conduits.

*Graeme Lane is a telemetry and automation product specialist with Automation Group. Automation Group specialises in providing electrical and automation products to utilities, mining and energy sectors as well as providing comprehensive support and technical services to contractors, integrators and end users.