Connecting Wireless Temperature Controllers

Modern industrial temperature controllers are not just simple thermostats, as their earlier counterparts were. With the ability to control upwards of a hundred parameters, the latest industrial temperature controllers allow users to set not only temperature points, but also program alarm settings based on adjustable ramp parameters. Users can select the RTD or thermocouple they want to use for collecting data, while setting limits on the set points.

With the advent of digital temperature controllers, users can configure them with a physical interface. Although, initially, the design of some models allowed them to connect to nearby computers through a wired link, the later models of temperature controllers come with Bluetooth enabled.

Traditionally, the physical interface of temperature controllers featured two to five buttons that allowed the user to set the various parameters for the controller. With the limited three to four character LED display on the controller, the user had to either know the button combinations or refer to a manual during the process of setting up the parameters.

Connecting earlier temperature controllers to PCs through wired serial interfaces presented other problems. It required the PC to be near the controller, as the interface and cable could cover only limited distances. This meant the PC had to operate in the noise and dust of the industrial environment, reducing its operational life. Cables connecting the two were prone to electromagnetic interference, and a tripping hazard. Most modern PCs come with only USB connections, and do not have serial interfaces any more, complicating the situation further.

Bluetooth enabled industrial temperature controllers have solved the above problems with ease. Several controller can connect to one mobile device with an app using Bluetooth—a short-range connecting technology. As the user brings the mobile device within range of the controller, he or she can ping the controller to confirm the specific device to interact. The app on the mobile allows the user to interact with the controller for viewing and setting all its parameters and for reviewing any of its error messages.

With the app interface offering greater graphical flexibility, the user can read the error messages and parameter names in plain text. Moreover, he or she can access in-line help for further understanding the function of each parameter and its permissible settings.

The graphical app interface allows the user to set up the temperature controller easily. It does not require the user to page through a manual or memorize the settings. No cables or other inconvenient interfaces are necessary for using these modern mobile interfaces.

With the unprecedented growth of cloud-enabled devices and the Internet of Things, there are concerns about information security in wireless connectivity. Using Bluetooth technology in industrial interconnections has its own advantages. Bluetooth is currently unable to connect to LAN, industrial Ethernet, or to cloud services, and is therefore, secure to that extent.

Furthermore, Bluetooth technology functions over short distances, and communications are limited to within 70 feet, limiting long-range interference. Moreover, users can protect controllers with passwords. Users can select the parameters on the controller that the password will protect, and a remote user cannot change them through the app.