"The deal was we had to tell you exactly what's going on, and we had to give you recommendations about what to do about it." Emerson's Dale Perry explains how the company applied Human Centered Design to its user interface to simplify protocol complexity.The interface has taken the inherent complexity of a Foundation fieldbus network, for example, and really simplified it, Perry says. The user interface focuses on the task at hand, independent of the protocol, measurement or delivery method. "It all starts with a measurement," Perry says. "How am I going to get that measurement? What's the protocol that I'm going to use to get it?"
The easy way to go is with the HART protocol, which requires no special tools or training, Perry says. But depending on the application it can be slow, prone to on-scale failures and can leave data stranded. Further, power constraints can limit functionality, Perry points out.
Foundation fieldbus, on the other hand, is designed to be a process LAN. It's designed to pass data back and forth; it provides an unlimited number of variables; and it is an active protocol. But it's complicated. It requires special tools like bus analyzers and oscilloscopes; you have to know where devices are located; considerable training is required; and device descriptors have no backward- or forward-compatibility.
The HCD user interface brings fieldbus and HART together in a simple way for users, enabling both functionality and simplicity, Perry says. It focuses on the task that needs to be done, providing a consistent graphical look and feel that is technology-independent. Built-in wizards replace the need for operators to know what the relevant variables are. "It's the Google of user interfaces," Perry says. "It's very clean, but very, very useful."