In many mines in the world, no worker drives into the shaft without a modern wireless communication device. In harsh underground operations, Strata Worldwide's Miner Communicator CommTrac has prevailed in many places. The display unit, one of the central components of this communication device, was designed from the German display specialist ELECTRONIC ASSEMBLY.

Mining, especially underground operation, is not an industry like any other. Even in the 21st century, the mining of coal or ores is a dangerous activity in which the supervisor of coatings must always be informed about the situation on the ground. Not only to conduct the operation and to use miners like equipment as efficiently as possible, but also to have a complete picture of the situation in case of an incident: What happened? And where exactly in the underground labyrinth is every single employee? To this end, the US company Strata Worldwide, a recognized specialist for technically sophisticated products and technologies for improving safety in mining operations, has developed its own radio technology: CommTrac. The term refers to the terminals (communication nodes) as well as to the radio network established by means of these devices.

The battery-powered communication nodes of the CommTrac system build a decentralized wireless network; a backbone is not needed. The meshed network topology ensures that the system works even in case of malfunction. Communication takes place in text form, similar to pager; It can optionally be set up between individual network subscribers as a point-to-point connection or sent as a broadcast message to all subscribers. The participants can send freely formable messages; but you can also use schematized, pre-formulated texts and answers. With the CommTrack system, the head office can keep in contact with the individual miner, as well as vice versa. In addition, the miners can also activate each other underground.

At least as important as the communication is another function of the system: The devices make it possible to determine and track the position of their wearers. They automatically send their position data at intervals of 30 to 60 seconds. The management can thus always determine the position of each miner, even if this has moved since the last contact within the mine. The accuracy of the localization is 15 meters (50 feet) and better. The last known positions with the associated motion vector are displayed in the graphical user interface of the control station for days. This process is called "breadcrumb tracking", breadcrumb tracking - based on the tale of Hänsel and Gretel.
The miners carry lightweight, compact equipment that performs the communicator and tracker functions of the system. The user interface is designed for ease of use and therefore comes with few elements. By means of buttons in arrow form the miners navigate through the menus. At the same time, these keys are used to compose and send messages. An LED indicates when a text message has been received. The message itself is displayed on an LCD screen. Strata Worldwide engineers chose ELECTRONIC ASSEMBLY's EA DIP180B-5NLW semi-custom LCD graphics module to develop the device. At first, they were guided by the product features: they were looking for a compact display module that had the necessary robustness for operation underground. At the same time, the display should be easy to read, even in difficult lighting and visibility conditions. These conditions satisfied the LCD graphics module at 180x32 pixels. With its high-contrast blue-and-white Supertwist display, it leaves no doubt about the transmitted message even in a dimly lit, dusty environment. Even the extreme ambient temperatures underground can not harm the module; effortlessly it cope with the underground sauna-like temperatures up to + 70 ° C.The fulfillment of this requirement list put ELECTRONIC ASSEMBLY on the list of suppliers for the first time. When the product went into series production, the display specialist from Gilching (Upper Bavaria) showed that his skills are far greater than just supplying standard displays. The flexibility of the company with special requests enthused the safety technology company from Pennsylvania - ELECTRONIC ASSEMBLY supplies on customer request also custom-made products in small quantities. In addition, the Gilchinger convinced by high delivery reliability for years.

"Because these display devices make it so easy to implement a powerful display, we've also used it in another device version," said David Hakins, vice president of research and development at Stratas Electronic Safety Division. "At the moment we are considering using another screen variant of ELECTRONIC ASSEMBLY as part of the evolution of the communicator."

So that the miner is never cut off from communication during the day.

More information at the website for graphic displays or directly the data sheet of the EA DIP180B-5NLW.