Smart Factories and the Challenges of the Proximity Network
Wi-Fi and wired Ethernet have a well-developed set of deployment capabilities. 802.15.4 on the other hand presents a set of difficulties unlike those of Wi-Fi and wired Ethernet. 802.15.4 can often have a mesh topology bringing greater reliability, but also increased difficulty in setting up paths through the network. There are tools available to view the mesh topology and corresponding signal strengths to help identify single points of failure and weak links in the network.
5.2 Distributed Intelligence
Once IIoT Edge Devices and Gateways are placed and networking is established, the software needs to be distributed and configured. In some cases, the edge devices and gateways are programmed with the correct software at manufacturing, but often the software needs to be upgraded or configured at the time of install. The proximity network needs to provide the capability to upgrade and configure the edge devices and gateway without direct physical access.
6. LONG-TERM MANAGEMENT
The IIoT solution is not complete upon install. Changing conditions in the physical world sometimes cause unreliable data sources and failed IIoT devices. In addition, the solution may need to be upgraded with a new feature, bug fix or security patch.
Wireless networks will drop traffic at times and IIoT devices will die. A robust solution will not only detect failures, but also aid in pinpointing the root cause. For example, if the gateway is driving reliable data collection, it can also report when an edge device fails to respond. There also needs to be mechanisms to troubleshoot networking issues such as ping, trace-route, topology views, signal strength views, etc.
Typical OS ' s such as Linux allow the user application to be upgraded independent of the underlying OS, network stack and drivers. This creates a great deal more robustness in the upgrade process. Typical embedded software is treated as " firmware ", i. e. software that isn ' t upgraded often or remotely. IIoT Edge Devices, however, often need a mechanism to be upgraded remotely and securely. It would be very desirable to upgrade the " user application " logic separate from the networking logic even on these edge nodes to limit the possibility of bricking the units.
7. CONCLUSIONS
The proximity network and the corresponding IIoT gateway and edge devices represent much of the complexity in building out a full Smart Factory solution. There are solutions to this complexity, but they must be picked by first considering the use case and various integration challenges to help choose the connectivity technology. Once the connectivity technology is chosen, there remain the problem sets of distributed intelligence, deployment and long-term management that must be considered during the design phase of a solution.
IIC Journal of Innovation- 75-