to allow an easy addition of nodes and a network expansion
The network typology must be compatible with the network information system of the industry. In this way, the hybrid solutions potentially ensure the best network performances and flexibility. Figure 1.2a shows an example of a hybrid extended star network, constructed by merging an extended star with a mesh network, by showing an example of network reconfiguration in cases of connection failures, where the automatic principle of node commutation is managed by an intelligent algorithm detecting and predicting system failures (example of direct interaction between processing layer and production machine layers). The cases of Figure 1.2b–e are related to a possible configuration of the data transmission of a part of the network of Figure 1.2a. This example highlights the importance of adding nodes to avoid the transmission problem. The solution to add nodes to the local network must be “weighted” with the decrease of performance due to the increased complexity of the new hybrid network. The prediction of possible failures of nodes, allows to change anticipatedly a linking configuration, thus avoiding data interruptions, and preserving production control. In the prediction calculation, sensors play an important role because they detect operation conditions of production lines, status machines and product tracking. In Table 1.3 and Table 1.4 are listed the main specifications of traceability sensors able to detect the product in each production stage, and the main characteristics of transmission protocols, respectively. Solutions for the actuation are the plug and play (P&P) solutions and programmable logic controller (PLC) hardware interfaces. For P&P systems the hardware and software components are downloaded and installed at or before run‐time. The supervisory control and data acquisition (SCADA) [30] systems are able to read production data and transmit the setpoints to the PLCs. SCADA systems typically are implemented to control system architectures by graphical user interfaces (GUIs), and behaving as a supervisor of peripheral devices such as PLC, and proportional integral derivative (PID) controllers interfacing process plant and production machinery. Typically, SCADA adopts visualization tools and synoptic graphics for real‐time data display.
Figure 1.2 Example of hybrid extended star network and failure system reconfiguration for a secure production monitoring: (a) hybrid network structure by extended star and mesh network; (b) normal configuration for data transmission to the manager central node (transmission from node 3 to node 1); (c) example of reconfiguration for an interrupted linking between node 1 (network coordinator) and node 2; (d, e) examples of reconfiguration for interrupted links between node 1 and node 2 and between node 1 and node 4 simultaneously.
Table 1.3 Main specifications of sensors used for traceability.
| Sensor type | Main specifications | References |
|---|---|---|
| Barcode | Optical laser reading identifying only type of itemOnly read<20 of characters of data capacity | [16, 17] |
| QRcode | Optical laser reading identifying only type of itemOnly readUp to 7089 characters of data capacity | [17, 18] |
| RFID | Radio frequency detection system100–1000 characters of data capacityRead and writeStandards: 125–134 kHz (LF); 13.56 MHz (HF); 866–915 MHz (UHF); 2.45–5.8 GHz (microwave)Active tags (100 m reading distance, 64 byte–32 KB of memory capacity)Passive tags (1 m reading distance, 48 byte–2 KB of memory capacity) | [16, 17,19–21] |
| NFC | Distance of communication: few cmTechnology: RFID basedFrequency: 13.56 MHzCommunication: two way | [21] |
| iBeacon | Bluetooth Low‐Energy (low power consumption)1 m ± 70 m wireless range | [22, 23] |
NFC, near field communication; RFID, radio frequency identification.
Table 1.4 Main specifications of sensor transmission protocols.
| Standard | Main specifications | References |
|---|---|---|
| ZigBee | WirelessIEEE802.15.4 standardWPANFrequencies: 868 MHz (Eu); 915 MHz (US); 2.4 GHz30−100 m wireless rangeNetwork type: star, mesh, cluster tree, peer to peerCapacity: 250 Kbit s−1 | [24–26] |
| WiFi | WirelessIEEE802.11 standardWireless local area networkFrequencies: 2.4–5.4 GHz1 km wireless rangeCommunication type: point to multipointCapacity: 54 Mbit s−1 | [26] |
| Bluetooth | WirelessIEEE802.15.1 standardWPAN networkFrequencies: 2.45 GHz1–100 m wireless rangeCommunication type: point to multipointNetwork type: starController: system on chipData rate: 1 Mbit s−1Capacity: 723.1 Kbit s−1 (versions 1.1 and 1.2); 3 Mbit s−1 (version 2.0)Bluetooth V4.0 | [21, 24] |
| RS‐232 | WiredLAN/PAN networkCommunication type: point to pointNetwork type: busCapacity: 75 bit s−1–115.2 Kbit s−1. | [27] |
| USB | WiredLAN/PAN networkCommunication type: point to pointNetwork type: tree, busCapacity: 12 Mbit s−1 (version 1.1); 480 Mbit s−1 (version 2.0); 4800 Mbit s−1 (version 3.0) | [28] |
| Ethernet | WiredLAN networkCommunication type: point to pointNetwork type: star, busCapacity: 10 Mbit s−1–10 Gbit s−1 | [29] |
| ZWAVE | Radio frequency technologySub‐GHz communications (900 MHz)Mesh networkNo coordinator nodeMaster/slave architectureData rates: 9.6/40/100 Kbit s−1 | [24] |
| Fifth Generation (5G) | Cellular network standardHigher throughputLower latencyArtificial intelligence capabilitiesVideo real‐time processing | [24] |
WPAN,
