WirelessHART has two big money plays. First, the one that will likely pay off the fastest, is the ability to add, simply and inexpensively, many more sensors than plants use currently in order to keep up with new regulations and tighter control requirements. And once the wireless mesh network is installed and paid for, adding additional measurement to the network becomes extremely cost-effective. This in itself is an excellent way to make sure that there is enough real-time data to ensure the success of advanced process control systems and complement the soft sensors some plant optimization systems can employ.
The second big money play for WirelessHART is asset management.
Asset management starts with the measurement assets in the field. Thirty million HART-enabled devices are already installed, and the vast majority of them are connected to control systems that aren't equipped to receive the HART Communication digital signal. In addition, there are thousands of pieces of rotating machinery (pumps, motors, fans, etc.) from which it has been problematic to get even rudimentary data like temperature, pressure and vibration—because they are turning. So WirelessHART will permit more than just "instrument" maintenance in the asset management system. It will permit many other, non-traditional measurements to be input directly into the asset management system.
Current asset management solutions require that operators and technicians equipped with mobile data devices do rounds—an exceptionally expensive use of human resources. Equipping position sensors, low- and high-alarm switches, vibration, pressure and temperature sensors on rotating machinery with WirelessHART communication will allow operators to spend their time doing more high-value work than being a "clipboard jockey."
Making It All Work
It is all about interoperability. The insistence of the HART Communication Foundation on interoperability, which Ed Ladd, director of technology programs for the Foundation, defines as, "Freedom to use any manufacturer of HART devices, and mix manufacturers and products in the same network," has been critical to the HART protocol becoming ubiquitous—with more than twice the number of installed HART-enabled field devices than the next nearest competing fieldbus.
Ladd continues, "Controllers use the same universal commands to communicate with all devices, and there are standardized diagnostics in every device. The same tools work with wired and wireless devices independent of the manufacturer with a goal of one EDD per device to work on all EDD-enabled hosts. Users have the freedom to use any revision—of the Protocol, of the device—without mandatory upgrades to tools or applications."
Because WirelessHART is HART, applications like the MACTek Bullet application at Progress Energy described in the previous article, where multidrop wired HART and WirelessHART are combined to provide the solution to the test department's issues with obsolete devices, just work. There's no finagling and no special or custom interfaces because it is all HART and that means interoperability.
Gerrit Lohmann, Pepperl+Fuchs' wireless product manager, says it well. "As the pressure continues to grow to optimize in a cost-effective manner, the stranded HART data contained in legacy instruments will be extracted via the customer's existing hardware, through a HART multiplexer or by the latest WirelessHART solution."
Ira Sharp, product marketing lead for wireless for Phoenix Contact, agrees. "This extra information can be used for predicative maintenance and more effective scheduling of maintenance, and provide a more accurate record of the devices being used in the field and their age for asset management."
Emerson's vice president of wireless, Bob Karschnia, points out, "What's key is understanding who will use the stranded data and what they will do with it. A THUM adapter enables the right information to easily get to the right people at the right time. This information might not have been important to the control scheme, but it is likely to have high value to others. Wireless unlocks this information in a cost-effective manner without complicating the control system."
"Remote wireless access to the HART devices allows engineers and technicians to remotely configure devices from a central location," says ABB's product manager for asset management and wireless, Eric Olson. "Beyond making the configuration task more convenient, it also saves time and reduces potential wiring mishaps by not having to use a field handheld to make the configuration changes."
This is a clear improvement for maintenance and asset management, he says, because, "It also allows for better documentation as the device configuration can be saved, printed, and if a device needs replacement, the configuration can be restored quickly. Many devices support a simulate function that can be initiated remotely via wireless to verify the device installation and system connection from a single location. This saves time as technicians no longer need to roam the plant to perform these tasks. And, of course, all of the wireless devices can be monitored remotely to verify their operation."
Because of the demand for increasing plant and unit optimization, most large vendors of control systems have released asset management software that integrates with the control system software they sell. The integrated and interoperable diagnostics in every HART-enabled field device are critical to economical asset management. It simply isn't economically possible to send operators and technicians out with handheld devices to download diagnostics from devices—and make sure that the data is correct. With HART it is easy, and with WirelessHART it is easy to do for any installed HART-enabled field device, from pressure transmitters to valve actuators to process analyzers. The elimination of operators making rounds to record process measurements manually not only improves process operations, but also saves time and increases operator safety!