Members of today’s society use smartphones and tablet PCs everywhere, and expect similar user interfaces from other appliances and machines. Not only is the industry prompted to use high-definition, thin-film-transistor (TFT) displays in an increasing number of applications, the displays must also allow large amounts of information to be presented in a relatively small area.
High-end displays at direct eye level in elevators capture passengers’ attention and shorten their perception of time spent waiting for a lift to arrive, as well as riding time. In addition, modern displays can share useful information with passengers about the elevator and building. Apart from familiar status reports, such as current floor number and riding direction, almost all conceivable messages can be displayed. These could include, for instance, “Use the emergency exit in case of fire” or “Elevator is being serviced” or notes about special rides like bed transports in hospitals or safety reminders, such as “Caution – door closing.”
Operators of elevators in industrial settings have to cope with many major challenges. These go beyond service life and long-term availability to include the high number of interfaces and protocols that need to be adapted for each application. This requires high-capacity microprocessors with low energy demand and minimal heat production.
CANopen-Lift as Elevator Interface
Apart from having an appealing and modern look, a display must primarily provide the passenger with required and useful information. This representation requires signals for the floor number, ride direction, overload or special ride. In the past, this was achieved by use of discrete signals that had to be wired from the controller to every display. To meet today’s industrial requirements and pare work down to a minimum, displays may be connected via the open standard CANopen-Lift network. This offers an entire scope of lift-system information for the displays by only accessing the field bus of the elevator. Some of these features are the elevator’s current position and actual speed for passengers traveling in a high-rise elevator.
CANopen-Lift also enables displays to analyze ride movements by themselves. Hereby, warnings such as “Mind your step” can be given when the car floor is not level with the landing floor.
In addition, the field bus provides information on the current load, which commonly comes into use on displays in goods lifts. However, it is also useful in case of an elevator malfunction involving entrapped passengers. In this case, hall-call displays at the main floor can show the “Out of order” notification and important information about the current position and load, as well as the safety gear being tripped. This information allows the engineer to rescue entrapped passengers in less time.
High-end displays at direct eye level in elevators capture passengers’ attention and shorten their perception of time spent waiting for a lift to arrive, as well as riding time.
The standard CANopen-Lift network allows prioritized calls to be made, loading times to be activated and access control to be transmitted when the display is equipped with a touchscreen. Access restriction is then possible by entering a personal identification number or through the network in a variety of scenarios by assigning calls, priorities and door times at certain times of the day.
Web-Based Display Configuration
The configuration of displays presents another challenge. Often, a restricted scope of functions or complicated tools for many adjustable functions are offered. To demonstrate the advantages of displays supporting the CANopen standard, an example based on the display product flexyPage will be given. With a combination of high-capacity hardware and low energy demand, flexyPage displays suggest a new approach using mobile processors combined with many standardized interfaces from the industrial environment, which are freely customizable via an easily operated web surface.
A configuration meeting the application requirements needs to be made to display information on an elevator display. Formerly, manufacturers typically provided a configuration program developed for Windows PCs. The created configuration files then had to be stored on an SD card or USB flash drive plugged into the displays. flexyPage displays are configured on a web basis, meaning that every current web browser installed on every computer, tablet or smartphone can be used for configuration purposes. No special installation is needed, and, since the configuration dialogues are directly available via the display, they are always up to date and match the display’s firmware.
Functions such as general elevator information, output of sensor data (position, weight and speed), multimedia data and web services are no longer available via one single application, but through widgets. These small programs with allocated functions occupy only part of the display layout, so they can be located anywhere on the screen. Owing to the free selection of different widgets and their adaption, many applications meeting a wide variety of requirements can be easily realized.
What is more, each displayed function can be activated and respectively deactivated in a time- and event-driven mode, which allows widgets to be activated or deactivated whenever certain signals occur. The event control can, for instance, be used to display evacuation instructions (instead of multimedia advertisements) during a fire.
Due to the fact that the development of flexyPage displays has been focused on a connection to the Internet as a basis for a large number of new functions, the display can be configured remotely via the flexyPage portal when linked to the Internet. A connection is achieved exclusively via a safe and encrypted virtual private network connection, which does not necessarily have to be installed by the user.
The configuration surface can be accessed from every current web browser and used to update pictures in a slideshow or the menu of a restaurant, for example. Apart from remote configuration, the Internet link makes it possible to display web services, such as the latest news from a Rich Site Summary feed. The widgets can be freely located on the screens, thus allowing complex applications to be realized with ease.
Installation with CANopen
When an elevator does not yet support the CANopen standard, signals are provided to the displays via external input/output modules. In case of modernization, networking via the CAN bus offers many benefits. If a TFT display is to be retrofitted in the car, the necessary signals must be made available by the controller. If there are no sufficient free wires in the traveling cable, a new one must be installed. As opposed to this, flexyPage displays using the standard CANopen-Lift allow the input/output modules to be directly installed where signals are available – for example, in the controller cabinet. Only two cables are needed to connect the display with the CAN bus.
Supplementary to this, the appropriate sensors can be directly connected to the bus when a retrofitted display is expected to display the load, location or speed. The respective assessment is carried out by the flexyPage display.
Networking of components via the CAN bus offers many benefits and possibilities for both new elevator systems and modernizations. ELFIN GmbH’s innovative flexyPage displays are a good example. The Internet is not only used to display websites, but also make other web services and a remote-control feature available.
Jörg Hellmich is managing director of ELFIN GmbH in Germany with extensive experience in the elevator industry.