Learning path
Industrial Networks Tutorials
Every layer of a modern plant depends on its networks: PLCs talk to I/O and drives, SCADA and MES read controller data, and edge devices send data to historians and the cloud. This learning path explains OT network design, the protocols that connect industrial systems, and how to secure and troubleshoot them.
1
Network Fundamentals
- Industrial Network Design for OT Engineers Networking explained for automation engineers: managed switches, IP addressing, VLANs, routing and NAT for machines, zones and DMZ, firewall rules, ring redundancy, multicast and IGMP, QoS, fibre vs copper, NTP/PTP, DHCP/DNS and diagnostics.
- Time Synchronisation (NTP/PTP) Why consistent time matters in plants and how to achieve it: NTP hierarchy and accuracy, IEEE 1588 PTP, GNSS time sources, Windows and Linux time services, PLC clocks, UTC and time zones, security, and a troubleshooting guide for clock drift and timestamp problems.
- Industrial Communication ProtocolsRelated guide
- DCS Networks and RedundancyRelated guide
2
Fieldbus and Industrial Ethernet
- HART Protocol How HART works: FSK signalling on top of 4-20 mA, loop resistance requirements, primary and secondary masters, universal and device-specific commands, dynamic variables, burst and multidrop modes, DD/FDI, WirelessHART, HART-IP, asset management and troubleshooting.
- Modbus RTU and Modbus TCP A practical Modbus guide: data model and register addressing, function codes, RTU framing and RS-485 wiring, Modbus TCP and the MBAP header, 32-bit values and byte order, exception codes, security and a troubleshooting checklist.
- PROFINET How PROFINET works: IO controllers, IO devices and supervisors, GSDML files, device naming and address assignment, RT and IRT communication, conformance classes, MRP and system redundancy, PROFIsafe, installation rules and troubleshooting.
- EtherNet/IP and CIP How EtherNet/IP works: the Common Industrial Protocol (CIP), scanners and adapters, explicit and implicit messaging, RPI and connection timeouts, unicast vs multicast, EDS files and electronic keying, DLR, CIP Safety, CIP Security and troubleshooting.
3
OPC UA
- OPC UA Explained A practical guide to OPC UA for automation engineers: client/server and PubSub, address space and information models, subscriptions, security modes and certificates, companion specifications, OPC Classic migration, design tips and troubleshooting.
- OPC UA Certificate Errors Step-by-step troubleshooting for OPC UA certificate and security errors: BadCertificateUntrusted, BadSecurityChecksFailed, BadCertificateTimeInvalid, hostname and URI mismatches, revocation errors, user token rejections, with verification and prevention.
4
MQTT and IIoT
5
Connectivity Products
6
Security and Certificates
- Certificates and PKI for OT Certificates explained for automation engineers: X.509 fields, PEM, DER, CER, CRT, PFX/P12 formats, root and intermediate CAs, private keys, thumbprints, revocation, where OT uses certificates (OPC UA, MQTT, HTTPS, VPN), plant PKI design and renewal planning.
- ISA/IEC 62443 CybersecurityRelated guide
- PLC SecurityRelated guide
7
Troubleshooting
- Bad Tag Quality and Communication Failures A systematic method for troubleshooting bad or stale tag quality, communication failures and data gaps between PLCs, OPC servers, SCADA, historians and MES: symptoms, likely causes, diagnostic steps, resolution, verification and prevention.
- OT Network Troubleshooting How to troubleshoot industrial network problems safely: physical layer and cabling, switch port diagnostics, duplicate IPs and VLANs, routing and firewalls, port reachability, DNS, packet capture with port mirroring, and precautions for fragile OT devices.