About 150 years ago, L. L. Zamenhof created Esperanto to be an international language that the entire world could adopt. While his aims were noble, it didn’t catch on. Process manufacturers have had similar problems because instrument and device-level industrial networks can use any one of various incompatible protocols to exchange data. But now, market forces, rather than simple good intentions, are settling on WirelessHART® as a practical method for making these types of networks much easier and less costly to set up and maintain.
Some might respond, “WirelessHART is fine for instrumentation and smart valve controllers, but what about discrete devices that need connections to remote I/O? We need those too.” This is a valid point since a protocol that is truly universal must support all industrial instruments and devices, and the way WirelessHART can handle discrete devices is the subject of my article in Process Instrumentation, Monitor Any Signal from Anywhere.
In the past, only instruments and other equipment with WirelessHART native connectivity, or with a WirelessHART THUM adapter installed, were able to connect with a WirelessHART network. But now, with the recent introduction of Emerson Rosemount 702 and 802 WirelessHART remote I/O devices, many other types of equipment can be controlled and monitored from control rooms and other locations.
So how do these Rosemount™ 702 Wireless Discrete Dual Input Transmitter and Rosemount 802 Wireless Multi Discrete I/O Transmitter remote I/O devices help? First, they support up to two or eight discrete devices, respectively, with each channel configurable to be an input or an output. Normally, these devices are relatively close together, such that they can be wired easily to the transmitter.
Many of these assets have access to electric power for actuating or driving the device itself, but providing wired control infrastructure to all these points is often uneconomic. Typical assets requiring remote monitoring include:
- Motor operated valve (MOV) control and position monitoring
- Manual open/close or on/off valve monitoring and control
- Pump monitoring and control.
These applications, and many more, each have a significant number of discrete status signals and control points associated with them, which combined with their locations, is driving the demand for wireless discrete control and monitoring.
Each transmitter sends/receives data from its group of devices on a single wireless signal, where it can be connected to a host, such as an automation or asset management system. With the security and reliability of WirelessHART technology, both the Rosemount 702 and 802 transmitters offer access to discrete points that are not connected to the control system due to wiring costs and lack of I/O. Both Rosemount WirelessHART Multi Discrete Transmitters are rated for operation in hazardous areas, environmentally protected, and powered with the Emerson 701P SmartPower™ Module or by external 10-30 Vdc line power.
Historically, being able to monitor the status of widely distributed assets was often not feasible with wired devices, but advances in technology have overcome these limitations. Monitoring and responding to any signal from anywhere provides a better understanding of processes and asset status, while also supporting a safer working environment.
For more information, visit Emerson’s Industrial Wireless Technology pages at Emerson.com. You can also connect and interact with other engineers at the Emerson Exchange 365 community.
