Industrial Networking & Communications Glossary
Industrial Ethernet, cellular and radio telemetry links, network hardware, and the communications layer under SCADA. 69 terms in this topic - each defined in plain English on its own page.
Below every protocol is a physical link, and for remote operations the link is often the hardest part of the job. This topic defines the industrial networking layer - Ethernet, switches, and network resilience on the plant side; cellular, radio, and satellite telemetry on the remote side - plus the RF and link-budget vocabulary that determines whether a far site stays connected. Protocol-level terms live in Industrial Protocols; this is the layer beneath them.
69 Terms
What is 802.1AS gPTP in time-sensitive networking?
The TSN time-sync profile that elects a grandmaster clock and shares one time base so scheduled and IT traffic converge.
Read → GlossaryWhat Is an APN?
Access Point Name - how public vs private APNs route cellular SCADA traffic - explained.
Read → GlossaryWhat Is Cellular Band Locking on a Remote Gateway?
Forcing a modem onto one LTE band or tower to stop it hopping between weak cells and dropping the link.
Read → GlossaryWhat Is Bandwidth Throttling?
Deliberate rate limiting - carrier-imposed vs operator-imposed - and how QoS keeps critical SCADA traffic moving.
Read → GlossaryWhat is a broadcast storm in an OT network?
A runaway flood of looping frames that can knock a flat control network offline; stopped by storm-control and loop prevention.
Read → GlossaryWhat Is Carrier Aggregation in Cellular Telemetry?
How LTE-Advanced bonds multiple bands to lift a remote gateway's throughput for historian sync and firmware pushes.
Read → GlossaryWhat is a cell/area zone in an industrial network?
The lowest control segment holding a machine's PLC, I/O, and HMI, how zones connect, and why cells contain faults.
Read → GlossaryWhat Is Cellular Failover?
How a remote site auto-switches to a backup link when the primary drops - active vs passive and dual-carrier designs.
Read → GlossaryWhat Is a Cellular Gateway?
The industrial 4G/5G router that connects remote RTUs, PLCs, and flow computers to SCADA - explained.
Read → GlossaryWhat Is a Cellular Modem?
The LTE/5G radio inside every cellular gateway - generations, bands, and modem vs gateway - explained.
Read → GlossaryWhat Is Cellular Signal (RSSI)?
Cellular signal strength in dBm, and how RSSI compares to RSRP, RSRQ, and SINR on LTE - explained.
Read → GlossaryCellular vs Satellite vs Radio Telemetry
Coverage, latency, bandwidth, and cost of the three remote SCADA backhauls, and how to choose - compared.
Read → GlossaryHow do I choose a network topology for a SCADA system?
A decision guide weighing star, ring, bus, and mesh against cost, distance, fault tolerance, and site layout.
Read → GlossaryWhat is a control network in a DCS?
The dedicated, deterministic, redundant tier linking DCS controllers, I/O, and stations, kept separate from business IT.
Read → GlossaryWhat is a daisy-chain topology in an industrial network?
Linear device-to-device wiring via two-port switches, its cabling savings, cascade risk, and how it becomes a ring.
Read → GlossaryWhat is a data plan overage on a SCADA SIM?
How a chatty poll rate or stuck retry loop blows past a pooled-data cap, and how to budget bytes per site.
Read → GlossaryWhat Is a Default Gateway in a SCADA Network?
The router address a device uses to reach off-subnet destinations, why a wrong gateway lets a PLC ping locally but never reach the cloud, and how it fits the cellular router at a remote pad.
Read → GlossaryWhat is a Deny-by-Default Firewall Rule?
Configuring OT firewalls to block everything and permit only named, justified flows so segmentation actually holds.
Read → GlossaryWhy does my cellular SCADA gateway keep dropping offline?
Triage RSRP/RSRQ signal, APN and SIM issues, data caps, carrier band drops, and a watchdog reboot loop.
Read → GlossaryWhat is deep packet inspection of industrial protocols?
Reading past the TCP header into Modbus, DNP3 and EtherNet/IP payloads to see function codes and setpoint changes.
Read → GlossaryWhat Is Dual-SIM?
Two carrier SIMs in one modem with automatic switchover - carrier redundancy for remote sites, explained.
Read → GlossaryWhat is dynamic DNS for remote sites?
Keeping a stable hostname pointed at a gateway whose public IP changes, and why a fixed-IP SIM is often preferred.
Read → GlossaryWhat Is an Edge Router?
The boundary device that connects a remote site to the WAN and handles NAT, firewall, VPN, and failover - explained.
Read → GlossaryWhat is a failover hold-down timer in dual-SIM failover?
The dwell time that stops dual-SIM or dual-WAN failover from flapping back and forth on a marginal link.
Read → GlossaryWhat is a flat network and why is it risky in OT?
An unsegmented OT network where every device reaches every other, letting malware and broadcast storms spread unchecked.
Read → GlossaryWhat is full packet capture and PCAP retention in OT?
Recording every packet to a rolling PCAP store for forensic replay, and the storage-versus-rewind trade-off.
Read → GlossaryWhat is gateway uplink payload batching?
Coalescing many readings into one larger message to amortize per-message overhead, with a batch-window latency tradeoff.
Read → GlossaryWhat is gear mesh frequency analysis?
Reading the tooth-mesh frequency and its sidebands to diagnose gear wear, eccentricity, and a cracked tooth.
Read → GlossaryWhat Is Half-Duplex vs Full-Duplex?
One direction at a time vs simultaneous, and how turnaround delays limit polling on RS-485 and radios.
Read → GlossaryWhat Is a HART Multiplexer?
The panel device that pulls digital HART data off many 4-20 mA loops for asset management.
Read → GlossaryWhat is a HART signal repeater?
A device that regenerates a weak HART digital signal on long or high-capacitance cable runs.
Read → GlossaryWhat is a hub-and-spoke topology in a SCADA network?
One central SCADA host polling many dispersed remote sites over radio, cellular, or VPN, with bandwidth and single-hub risks.
Read → GlossaryWhat is IGMP snooping in a SCADA network?
A switch feature that delivers multicast only to subscribers, stopping the floods that cause EtherNet/IP I/O timeouts.
Read → GlossaryWhat Is an Industrial Ethernet Switch?
The hardened DIN-rail switch that ties field PLCs and RTUs together - managed vs unmanaged, explained.
Read → GlossaryWhat Is ISA-100 Wireless?
The ISA100.11a industrial wireless standard: secure self-healing mesh for field instruments, and how it compares to WirelessHART.
Read → GlossaryWhat Is Jitter?
Variation in packet delay, why it differs from latency, and how it disrupts polling on wireless SCADA links.
Read → GlossaryWhat Is Latency?
Network delay in SCADA, how transports compare, and why it matters for polling and remote control - explained.
Read → GlossaryWhat is a latency budget for remote control?
Allocating a total end-to-end delay allowance across the path to decide if closed-loop control over cellular is safe.
Read → GlossaryWhat Is Line of Sight and the Fresnel Zone?
Why a clear view is not enough and how the Fresnel zone and earth curvature set antenna height.
Read → GlossaryWhat Is LoRaWAN?
The low-power, long-range LPWAN for battery sensors, its data-rate limits, and where it fits monitoring - explained.
Read → GlossaryWhat Is the LoRaWAN Duty Cycle Limit?
The regulatory cap on sub-GHz airtime that limits reporting frequency and downlink, and how it shapes payload sizing.
Read → GlossaryWhat is LPWAN uplink versus downlink asymmetry?
Why LPWAN favours telemetry uplink and limits downlink, making it poor for fast remote control.
Read → GlossaryWhat Is LTE Cat-M1?
The mobility-capable, higher-throughput cellular IoT tier, when to pick it over NB-IoT, and its role in RTU telemetry.
Read → GlossaryWhat is the difference between a managed and unmanaged industrial switch?
Unmanaged switches just forward traffic; managed switches add VLANs, ring redundancy, port security, and diagnostics.
Read → GlossaryWhat Is a Media Converter?
The device that bridges copper Ethernet to fiber for distance and noise immunity - and how it differs from a switch.
Read → GlossaryWhat is a mesh topology in an industrial network?
Nodes that relay for each other for self-healing multipath resilience, and where wireless mesh like WirelessHART fits.
Read → GlossaryWhat Is Network Redundancy?
Ring topology and RSTP that heal a broken link automatically so one cable fault never downs a site - explained.
Read → GlossaryWhat Is a Null Modem Cable?
The crossover serial cable that swaps TX and RX so two DTE devices can talk directly.
Read → GlossaryWhat Is an Omnidirectional Antenna?
The 360-degree master-station antenna that serves many remotes in a point-to-multipoint network.
Read → GlossaryWhat is a VLAN in an OT network?
Logical segmentation on shared switches to split PLC, HMI, camera, and vendor traffic, and its limits versus a firewall.
Read → GlossaryWhat is a plant information network?
The Purdue Level 3 tier that aggregates historian, MES, and reporting data above the control network.
Read → GlossaryWhat Is a Point-to-Multipoint Radio Network?
The star topology where one master radio polls many remotes over a single shared channel.
Read → GlossaryWhat is a power duty cycle in remote telemetry?
The fraction of time a load is on, which turns scary peak draw into the honest average that sizes a solar array.
Read → GlossaryWhat Is Power over Ethernet (PoE)?
Delivering DC power and data on one cable to field radios and cameras, with 802.3af, at, and bt classes.
Read → GlossaryWhat Are Cellular PSM and eDRX?
The cellular sleep modes that let a battery RTU stay dormant for hours, their power savings, and the reachability trade-off.
Read → GlossaryWhat is the Rapid Spanning Tree Protocol (RSTP)?
IEEE 802.1w loop prevention that blocks redundant links and reconverges in seconds using BPDUs and root bridges.
Read → GlossaryWhat Is a Redundant I/O Network and How Does It Keep Remote I/O Online?
Dual adapters, self-healing rings like DLR and MRP, and dual-media paths that survive a cut cable to remote I/O.
Read → GlossaryWhat is a redundant ring network?
A managed closed loop with a ring manager that survives a single break with fast self-healing recovery.
Read → GlossaryWhat Is an RF Link Budget?
The gain-minus-loss math that predicts whether a SCADA radio link will actually close.
Read → GlossaryWhat Are RSRP and RSRQ in Cellular Link Quality?
The two LTE reference-signal metrics a technician reads when siting an antenna, and how they differ from RSSI.
Read → GlossaryWhat is a screened subnet in an OT network?
The back-to-back dual-firewall architecture wrapping a SCADA DMZ, and why two firewalls from different vendors beat one.
Read → GlossaryWhat Is a Serial-to-Ethernet Converter?
The device server that puts legacy RS-232/RS-485 gear on an IP network - raw TCP vs virtual COM, explained.
Read → GlossaryWhat Is SIM Connectivity Management?
The platform that provisions, monitors, and pools cellular SIMs across a large telemetry fleet - explained.
Read → GlossaryWhat is a SPAN port vs a network TAP for OT monitoring?
How an IDS sensor gets a traffic copy: a switch mirror port versus an inline TAP, and why TAPs avoid silent drops.
Read → GlossaryWhat Is a LoRaWAN Spreading Factor?
The SF7-SF12 dial that trades range against airtime and battery, how ADR tunes it, and why high SF congests gateways.
Read → GlossaryWhat Is a Subnet Mask and CIDR for SCADA?
The practical minimum of subnet masks and /24 CIDR an automation tech needs to lay out a control network where every device reaches the SCADA host.
Read → GlossaryWhat is the difference between a VLAN trunk port and an access port?
Access ports carry one untagged VLAN to a device; trunks carry many tagged VLANs between switches, plus the native-VLAN gotcha.
Read → GlossaryWhat Is a Virtual IP Address in a Failover Setup?
The floating address that always points to the current primary node, making failover seamless to field devices.
Read → GlossaryWhat Is a Yagi Antenna?
The directional gain antenna aimed from a remote RTU site back to a distant master station.
Read →One Platform for the Field
Merobix is cloud SCADA for oil & gas - it reads the instruments and protocols defined here into one dashboard.
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All Glossary Topics
Browse the full 21-topic automation glossary.
Read Article → Deep DiveCellular vs Satellite vs Radio Telemetry
Choosing the communications layer for remote sites.
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The system these terms describe.
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