Radio instead of cable: According to this principle, switchgear and command devices can be flexibly combined with company IT, for example in picking zones or warehouses. This is implemented via the "Swave.net "network by steutethat integrates directly with the user's IT platforms. First applications are already available in FTS and E-Kanban systems, among others.
A compact AGV (Automated Guided Vehicle System) loads a box from the pick-up point to transport it to its destination. The employee in the dispatch warehouse requests the next commission. An installer removes the last container of an item from the mobile kanban shelf and triggers a replenishment order. These are three simple examples of the use of the wireless network Swave.net.
Compared to the first generation, the basic principle is retained: The radio system, which was developed for industrial applications, is limited to the irregular transmission of smaller data packets with extremely low energy consumption. Specifically, this means: Wireless switching devices of various types (position switches, foot switches, command devices, magnetic sensors, light sensors ...) are connected via access points to customer IT infrastructures - for example, to production planning and control (PPS), production data collection (BDE) or warehouse management.
Dynamic self-organization in the network
New in the second generation network is the optimized communication protocol. It works even more energy-efficient and organizes automatically an alternative route for data transmission, if z. For example, sending a message to the nearest access point should fail. This ensures a high transmission reliability.
The interface between the customer-specific application and the Swave.net hardware is the Swave.net driver software, which manages the complete radio system. The access points are configured via their user interface on a web server (Web UI) for the respective request so that the user software does not assume any administrative tasks in the Swave.net system. Also changes in the network can be easily realized in this way. The database can also be adapted to the individual requirements and wishes of the user
Other novelties of the second generation of Swave.net include the choice of three transmission frequencies: 868, 915 and 922 MHz. Thus, the wireless network meets the radio standards in Europe, North and South America, Australia and Japan and can thus be used worldwide.
Access points can be integrated into the IP network
The access points themselves are much more compact than the first generation. In addition, they are equipped with additional features including a wireless adapter. They can not only be connected to the application server but also integrated directly into the IP network via a web portal. Each access point can receive the signals from approx. 100 radio switching devices and forwards them, for example. B. via WiFi or Ethernet on. Power can be supplied via an external power supply or with an additional module via PoE (Power over Ethernet).
Bidirectional communication with new wireless terminal
So far, the radio signals that are transmitted always went in one direction - from the switching or command device via the access point to the corporate IT. The communication becomes bidirectional with the new operator terminal or "Andon button". The user receives z. B. via the two-line display a picking order and then acknowledges him via one of the three freely assignable buttons.
Freedoms in the flow of information
An advantage of this new type of wireless network is first of all that you can dispense with the installation and connection of lines. This saves considerable costs, especially in extensive applications such as storage and order picking systems. In addition, the installation remains more flexible - new wireless switching devices can be integrated into the system at any time and configured with little effort. In mobile applications such as mobile kanban shelves, wireless communication creates the prerequisite for integration into the information flow.
Other radio technologies are retained
From the point of view of the wireless experts, Swave.net represents the next logical step in the integration of switchgear into the industrial data world. The customized network solutions with their own application servers and proprietary interfaces to the company IT offer new possibilities for the information and data exchange over the individual levels - in completely different industries and applications.
Due to the structure and properties of the network, intralogistics is in the spotlight, as the application examples already mentioned above show. For example, Steute has implemented a radio network in the shipping warehouse of a well-known kitchen manufacturer, as well as on the "Wireless Kanban" shelves of the assembly workstations of an Austrian sports equipment manufacturer.
There are several other applications in driverless transport systems. For example, SSI Schaefer uses such radio switching devices in its "Weasel" FTTS fleets. The manual loading stations for the Weasel are each equipped with a wireless position switch: The container actuates the roller lever of the switch and thereby requests the AGV.
Point-to-point connection retains authorization
The conventional radio switching devices with associated evaluation unit as a point-to-point connection will continue to retain their rights. They prove their worth where only a few switching or command devices are needed and where there are further requirements that a radio network can not (yet) fulfill. These include, for example, safety-related applications, explosion-proof radio systems and batteryless switchgear, which generate the energy they need to transmit the radio signal from the environment according to the principle of "energy harvesting".
The author is Joachim Hoitsch, Steute Austria.