Geof Brazier
Director of Development, BS&B Safety Systems
Q: What advantages can industrial users expect to realize by implementing wireless solutions?
A: Today’s wireless solutions can help users realize an increase in the amount of process information that can be economically collected for both monitoring and control purposes. Sensor technology has long been cost effective for common process parameters, such as pressure and temperature, but the implementation of these devices is often uneconomic due to both the direct and indirect cost of hard wiring.
Wireless solutions permit not only permanent collection of information, but also the implementation of temporary data collection for diagnostic or developmental purposes. This flexibility of wireless technology permits a more rapid response and a more accurate response to troubleshooting.
The freedom to inexpensively monitor any "change-of-state" or "analog" sensor from almost any location permits the plant engineer to justify the collection of "want to know" data and not just the "critical to process" information that supports investment in hard-wired systems. In the past, if plants wanted to monitor a pressure relief valve or rupture disc, for example, they had to run wire from the monitoring station to the source. Wireless solutions eliminate the cost and complexity of additional wiring and in many cases, reduces monitoring costs by 90 percent.
Q: What are some of the common pitfalls users need to be aware of when implementing wireless in an industrial environment?
A: Understand the environment for the optimum function of wireless solutions. A reputable manufacturer will offer the ability to administer an onsite survey to verify where wireless modules are best installed to secure data transmission.
Infinite battery life does not exist; the convenience of a battery-powered wireless device makes them a natural first choice. However, when near-continuous data updates are required, battery life will be compromised. Selecting wireless technology that offers integral battery power with the option for external DC power is the best solution; the same hardware can be deployed throughout a facility with each application appropriately powered. Where needed, solar-derived DC power can be implemented.
There is a misconception that wireless technology is unreliable. Current generation-wireless solutions use self-testing protocols to ensure that a system remains active even when there may be no sensor data to transmit. Returning to the example of monitoring a rupture disc or pressure relief valve, where a simple closed/open switch is used, there will be no change-of-state of the sensor signal for perhaps years. A background heartbeat check is used to confirm that communication between system components is active with an alarm generated in the rare event of a loss of communication.
Q: What are some best practices users can employ to ensure effective application of their wireless solutions?
A: Process manufacturers can choose from several wireless technologies. Finding the best wireless solution for their individual needs starts with understanding the application that requires monitoring and asking such questions as:
• What is the process being monitored? This will determine the system ratio and whether a simple switch, analog, or pulse sensor will be used.
• Is the process housed in a hazardous environment? If so, the wireless solution chosen should have the Class I Division 1 rating.
• What is the operating range of the process? This will help determine what type of transmitters are needed and whether the transmitters will be elevated and used with optional external antennas.
• Also imperative for an effective application is open dialog with personnel groups who will support wireless installations including, maintenance crews, those responsible for monitoring, and the plant’s IT team.
Q: There is a lot of concern among industrial users about the security of wireless technology. What are some key best practices users can employ to ensure the security of their wireless platform?
A: Wireless systems with built-in encryption, authentication, anti-jamming, and other security measures offer the security of any software based electronic data system. Those systems that offer a unique identity number to each wireless module and use that number to verify the authenticity of each communication exchange are the most secure.
Q: How do you see industrial wireless evolving going forward? What can users look forward to in terms of new wireless capability in industrial plant environments?
A: Several distinct families of technology that will include at least the following:
• Wireless systems that are integrated with sensors, typically offered by sensor manufacturers as a means to leverage the sale of more sensors.
• Wireless systems that are independent of a sensor manufacturer, offering the flexibility to combine sensor types and brands into a single system.
• Stand-alone wireless monitoring systems that allow the plant engineer to independently collect ‘want to know’ as opposed to ‘need to know’ information from field devices
• Simple ‘point A to point B’ wire replacement devices that offer an alternative to hard wiring for low density sensor applications
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