A simple twist of the thumbwheel is all that is required to distribute I/O signals with ease over long distances – without the need for any software.
These special advantages offered by the Radioline wireless system from Phoenix Contact are now offered side by side with cable connection. This robust solution is suitable for use in many industrial sectors, from the process industry to infrastructure applications.
In numerous applications, the quantity of data and signals, which needs to be centrally controlled and evaluated, is continually rising. This statement applies, for instance, in the field of water/wastewater to upgrading elevated tanks, valve chambers, and pump stations. Accordingly, the vast majority of widely distributed facilities tend in the best case to be networked with the control centre via a minimum number of old data lines that are often working at or above capacity. Routing new cables to the stations, often located several kilometres away, can prove an expensive undertaking and is sometimes not even feasible. The Radioline wireless system enables existing data lines to continue to be used and wireless transmission to be established in various licence-free frequency ranges in order to ensure reliable communication. Combined cable-based and wireless operation is now available with immediate effect.
Link up to 99 stations via an RS-485 connection
For the simple and flexible distribution of I/O signals between all devices, Radioline enables up to 99 stations to be connected via a two-wire line. The data is exchanged via an RS-485 cable connection with no software configuration changes necessary. All the user has to do is assign a unique address to the head modules via the yellow RAD-ID. As the I/O expansion modules form a pair with the same address as a matching input and output, the signals can be input and output by means of I/O mapping. This allows several hundred analog and digital signals to be easily evaluated and used to control the application via two existing data lines between several stations. The maximum range of an RS-485 network is approximately 1,2 kilometres. By using repeaters or transmitting data over channels like Ethernet, fibre-optic cables, or SHDSL, the user can increase the range as desired.
Potential to bridge distances of up to 32 kilometres
The Radioline system addresses the specific requirements of industrial infrastructure applications and is based on the proprietary Trusted Wireless 2.0 technology. It closes the gap between WirelessHART, as a solution for the process industry, and the Bluetooth and wireless LAN standards established in factory automation. The Radioline system currently consists of four head modules and eight different expansion modules. There are three different licence-free receivers available as head modules. They can be used worldwide on the 2,4 GHz frequency band, in Europe on the 868 MHz frequency band, and in the U.S. and Canada on the 900 MHz frequency band. The fourth cabled head module can be integrated into a wireless network using a two-wire RS-485 series interface.
The user can connect the required I/O expansion modules to each head module. All of these modules offer channel separation and can be exchanged while in operation via hot swap. In a wireless network, operation of a maximum of 250 stations is possible, whereby each station can be extended by up to 32 I/O expansion modules. These enable the transmission of digital, analog or temperature signals. There can be four, six, or even eight independent channels per expansion module, depending on the model. Because of this, there can be up to 256 I/O signals per station. When the Radioline system is operated on the 2,4 GHz frequency, it can cover distances of up to five kilometres between two stations; when it is operated on the 868 MHz band, it can cover distances of up to 20 kilometres, and when it is operated at 900 MHz it can even cover distances of up to 32 kilometres.
Distribution of I/O signals using a thumbwheel
The RS-485 is often only networked locally within the station and the individual locations are then connected wirelessly. With this in mind, the Radioline system now also supports combined operation of wireless and cable-based stations. The local cable-based spur line allows the wireless network to be expanded. As it is a closed Radioline network, which connects the stations using various media, users across the entire system benefit from the advantages the wireless solution has to offer. In addition to simple start-up, it includes the distribution of I/O information using a thumbwheel as well as optional diagnostics.
Coexistence with other parallel wireless systems
As previously mentioned, the Radioline system is based on Trusted Wireless 2.0 technology, which allows numerous Radioline wireless networks to be operated in parallel and independently of one another. Furthermore, Trusted Wireless 2.0 facilitates coexistence with other wireless systems, such as Bluetooth or WLAN. 128-bit AES encryption protects data against unauthorised access. All wireless stations work automatically as repeaters so that even in challenging geographical conditions – for example, if a hill blocks the line of sight between two devices – a reliable connection can be established via other stations. The mesh network thus created not only enables large distances to be covered, but also automatic self-healing of the wireless network when stations go down. To increase connection stability, individual wireless modules, which do not include any I/O expansion modules, can also be installed as repeaters. As such, analog filling levels from an elevated tank or digital switching commands for pumps can be easily initiated and evaluated in the control centre.
Integration into a Modbus network
If the analog or digital signals are to be transparently input and output at another station, and also integrated into a central controller, the user can connect the Radioline system to a higher-level Modbus network. The controller installed there then processes the incoming data and outputs the switching commands in the Radioline network. Thanks to the direct connection via the Modbus protocol, the I/O expansion modules at the central Radioline station as well as the corresponding inputs and outputs on the controller are no longer needed. Automatic protocol detection enables cable-based stations to run at an optional Radioline master, or alternatively at a Modbus controller, without any configuration changes.
One stick for one-time global network configuration
Phoenix Contact offers free diagnostics and configuration software for the entire system to give support during installation by displaying the reception quality or mapping the network topology. In addition, the user can make further settings changes, such as adjust the transmission power or assign station names. Following start-up, the wireless network should be ‘locked.’ This ensures that any neighbouring device, which is within range and is wirelessly connected with the same system, does not create interference. For this purpose, user-friendly configuration sticks are offered which include a global one-time network configuration. The factory default settings of the wireless modules can be changed using the configuration software, while the stick only includes one-time configuration. The stick is used to lock the wireless network so that several thousand wireless networks can be operated in parallel without interfering with each other.
For more information contact Sheree Britz, Phoenix Contact, +27 (0)11 801 8200, [email protected], www.phoenixcontact.co.za
| Tel: | +27 11 801 8200 |
| Email: | [email protected] |
| www: | www.phoenixcontact.co.za |
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