Wireless Industrial Technology Consortium
The abbreviation WiTECK means "Wireless Industrial Technology Consortium", which is a publicly accessible non-profit organization and which serves the implementation of wireless standards in the automation of processes within factory production. Therefore, it pursues the goal of ensuring a technology within this industry that depends neither on manufacturers nor on platforms. WiTECK is an American invention by leading manufacturers of automation solutions and wireless components that exists since 2008. The registered offices of the organization are in the US State of Delaware.
The WiTECK Structure
Although this organization views itself as an open non-profit consortium, there are differences within the hierarchy, as two forms of members are distinguished:
- Promoter – With their initiation fee and annual contribution, the members carry the main load of the organization, regardless whether the funds are used for the development of WirelessHART or not. By accepting the costs, the source codes of the standards are available to the members for installation in their own products, and also the co-determination during meetings is kept within this group, which also includes the subdivision of the licensing agents.
- Adopter – This is a theoretical member group that at most in the future will consist of research laboratories, universities, agencies, and organizations for standardization. An annual contribution is due here too, which will offer access to programming interfaces, mailing lists, an internal FAQ platform, and the entire support.
The WiTECK Tasks
WiTECK also works with the fieldbus technology. Such bus systems connect the sensors, which are sensing elements, and the actuators, which are the control elements, with each other within a network to fulfill the purpose of communication to a control device. Here, standardized protocols are used as well, because when sending several messages via the same line, it must be regulated which identification receives the measurement values and commands according to which initiative. However, differing from previous organizations, the Wireless Industrial Technology Consortium does not adopt standards. Rather, the work of the consortium aims at implementing the specifications in a type of software that is in compliance with already specified standards. As a result, the greatest task the organization sets for themselves is the development and maintenance of software.
WiTECK and its invention WirelessHART
The work by WiTECk is currently based on the development of WirelessHART, which is also a software that is in compliance with already existing standards. With this technology, the development of a network is almost automatic. Planning is the sole exception here. Realiztion of its use for process and plant automation requires compatible field devices and gateways. A network manager is also necessary, which can be integrated on a separate PC and is located there in the gateway or controller. A mesh-network is created with these components, where the field devices take on the function of a router and manage the transmission of messages between other field devices and the gateway. Thus, a network can be expanded optionally, since the field devices only need to bridge the distance to the next field device. Furthermore, the development of such a software stack has the positive aspect that the interoperability can be secured and the development costs are also distributed.
Preventing Faults through the WiTECK Technology
Radio communication is automatically established for the WirelessHART software, which facilitates managing a network. The transfer is the same as for Bluetooth and WLAN. The faults, which the software tries to avoid, concern two main problems:
- The risk of collisions when using the WiTECK technology is avoided by using Time Division Multiple Access (TDMA). With this method, the information is transmitted by the field device only during specified time frames, so that the loss of data packets and collision of messages is avoided.
- Interferences with other radio systems is excluded through frequency hopping, where the radio modules of the respective field devices always jump between the channels 11 to 26, so that the channels that may be occupied by WLAN can be bypassed.
Additionally, in the WiTECK technology the robustness of the output signal is improved so that the data packets are not destroyed if, because of redundant transfer paths a time delayed message transmission or other interference factors occur.
The Aspect of Security with WirelessHART
In the development, WiTECK makes sure that there is a high degree of security. There are various steps to avoid errors and faults, as well as misuse through unauthorized access:
- Access to the network requires login by each field device via a “join key”, which can be issued only by the system operator.
- For each transfer process, session keys are issued, which are changed regularly.
- Generally, all messages are transferred encrypted.
- To avoid manipulation during the transfer, the data packages obtain a "Message Integrity Code" that must meet the expectations of the recipient to make sure the message is not discarded.
- During a change of the chronological sequence of a data transfer, the network manager must access the network key to make sure the instructions only reach the connected devices.
- The redundant transfer paths prevent frequency changes and denial-of-service attacks.