Blog Archive: August 2026
35 articles published in August 2026.
Everything Voltrus published in August 2026: "NATS JetStream Explained: Streams, Consumers, KV, and Core NATS", "NATS Client for macOS: Publish, Subscribe and Browse JetStream", "Web-Based HMI vs SCADA: Browser Dashboards for Machines and Plants". Practical guides and comparisons for engineers working with industrial automation tools, from protocol explorers to SCADA and HMI.
NATS JetStream Explained: Streams, Consumers, KV, and Core NATS
How JetStream streams, consumers, retention, acks and replay work, plus the KV and Object stores and a table for choosing between Core NATS, a stream and a KV bucket.
Read articleNATS Client for macOS: Publish, Subscribe and Browse JetStream
Looking for a NATS client on macOS? Compare the CLI, NATS Studio, Nui, and native GUI options. How to publish/subscribe, manage JetStream streams and consumers, and browse KV/Object stores without a terminal.
Read articleWeb-Based HMI vs SCADA: Browser Dashboards for Machines and Plants
How browser HMIs connect to PLCs, WebSocket vs polling, single-file deployment, and where an HMI ends and SCADA begins, with a decision framework for integrators.
Read articleHMI on Raspberry Pi: A Low-Cost Industrial Touchscreen Panel
How to run an HMI on a Raspberry Pi: kiosk mode, serving dashboards, connecting to PLCs over the network, and the watchdog + auto-start setup that makes a Pi a reliable industrial operator panel.
Read articleOEE Formula Explained with a Worked Example
The OEE formula broken down step by step. How to calculate Availability, Performance, and Quality, a full worked example, the ideal 100% benchmark, and the mistakes that inflate your score.
Read articleManufacturing Downtime Tracking: Measure, Classify, Reduce Stops
Capture downtime automatically, derive machine state from PLC signals you already have, keep reason codes honest, and read the Pareto that shows where the minutes actually go.
Read articleModbus Poll vs Modscan vs Modbus Slave: Which Master Tool to Use
Modbus Poll, Modscan, and Modbus Slave compared. Platform support, RTU vs TCP, master and simulator modes, pricing, and which Modbus master tool fits your workflow in 2026.
Read articleModbus TCP vs PROFINET: Choosing the Right Industrial Ethernet
Modbus TCP vs PROFINET compared. Real-time determinism, device discovery, configuration effort, vendor ecosystem, and when to use each industrial Ethernet protocol.
Read articleHow to Read Modbus Holding Registers (FC03): A Practical Walkthrough
How to read Modbus holding registers with function code 03. Slave ID, start address, quantity, the FC03 frame, 16-bit byte order, and 32-bit scaling explained.
Read articleEtherNet/IP ListIdentity: How Device Discovery Works (UDP 44818)
EtherNet/IP ListIdentity discovery explained. How a broadcast on UDP 44818 finds every CIP device, what the Identity reply contains, and how to browse devices on macOS.
Read articleCIP Explicit vs Implicit Messaging: When to Use Each
CIP explicit vs implicit messaging compared. Explicit (TCP 44818, request-response, tag reads) vs implicit (UDP 2222, cyclic I/O, RPI). Use cases, overhead, and when each wins.
Read articleEtherNet/IP Port 44818 Explained: TCP, UDP 2222, and Firewall Rules
EtherNet/IP port 44818 explained. TCP 44818 for explicit messaging, UDP 2222 for cyclic I/O, UDP 44818 for ListIdentity discovery. Firewall rules and security.
Read articleDNP3 vs IEC 60870-5-104: Power Utility Protocols Compared
DNP3 vs IEC 60870-5-104 compared. The two dominant power-utility SCADA protocols. Addressing, transport, event model, region, and which to choose for substations.
Read articleDNP3 Class 0, 1, 2, 3 Explained: Event Polling Strategy
DNP3 Class 0, 1, 2, 3 explained. Class 0 is a full snapshot; Classes 1-3 are prioritized event backlogs. How utility masters poll by class to retrieve only what changed.
Read articleDNP3 Select-Before-Operate (SBO): Safe Control Outputs
DNP3 Select-Before-Operate explained. Why SBO guards critical controls, how the select-then-operate two-step works, select timeouts, and direct operate for non-critical points.
Read articleOPC UA vs OPC Classic (DA): Why the Upgrade Matters
OPC UA vs OPC Classic (DA) compared. Platform-independent transport, built-in security, rich information model, and why migrating from COM-based OPC DA to OPC UA matters.
Read articleOPC UA Information Model Explained and How to Browse a Server
Nodes, references, the type system and companion specs, then a step-by-step walkthrough of browsing a UA server from GetEndpoints to a subscribed value, including on macOS.
Read articleOPC UA Security: Certificates, Encryption, and Auth Setup
OPC UA security explained. Security modes (None, Sign, SignAndEncrypt), security policies, X.509 certificates, mutual authentication, trust lists, and secure setup.
Read articleOPC UA Subscriptions and Monitored Items Explained
OPC UA subscriptions and monitored items explained. Publishing interval, sampling, data-change filters, and why subscribe beats poll for live monitoring.
Read articleSiemens S7-1200 vs S7-1500: Which PLC for Your Project
Siemens S7-1200 vs S7-1500 compared. Performance, memory, I/O count, motion, safety, PROFINET, price, and which Siemens PLC fits small machines vs large process lines.
Read articleS7 Protocol vs OPC UA for Siemens PLCs: Direct or Standardized
S7 protocol vs OPC UA for Siemens PLCs compared. Native direct access vs the cross-vendor standard, performance, security, setup, and when to use each.
Read articleHow to Read a Siemens S7 Data Block (DB) Over the Network
How to read a Siemens S7 data block. DB number and offset addressing, data types, the rack/slot connection, enabling PUT/GET, and reading S7-1200/1500 DBs.
Read articleBLE GATT Services and Characteristics Explained: How Every BLE Device Is Structured
The GATT data model end to end: ATT vs GATT, the Profile, Service, Characteristic, Descriptor hierarchy, UUID formats, characteristic properties, the CCCD, ATT operations, and a full byte-level walk-through of the Heart Rate Service.
Read articleBLE Pairing and Bonding: Security Explained
Pairing vs bonding, LE Legacy vs LE Secure Connections (ECDH P-256), the four association models, the STK/LTK key hierarchy, AES-CCM encryption, IRK-based privacy, Security Mode 1 levels, and how to debug auth failures on macOS.
Read articleMQTT Topic Design: Best Practices for Naming and Wildcards
MQTT topic naming rules, forward-slash hierarchy, the + and # wildcards, shared subscriptions, ACL security, and the anti-patterns that bite teams in production.
Read articleOPC UA Companion Specifications: How UA Models Real Industries
How OPC Foundation collaborations with industry bodies (VDMA, PLCopen, VDW, BACnet) add typed, domain-specific information models so multi-vendor equipment interoperates without per-vendor register maps.
Read articleOPC UA vs Modbus TCP: Which Industrial Protocol to Choose
Data model, security, discovery and scalability compared, plus what gateways between the two really cost and how to secure Modbus TCP when you cannot replace it.
Read articlePROFINET vs S7 Communication: What's the Difference
PROFINET IO and S7 communication are not competing protocols: they coexist on every Siemens controller. PN-IO is the deterministic fieldbus for cyclic I/O; S7 is the acyclic read/write protocol over TCP port 102. Ports, RFC 1006, RT/IRT timing, GSDML, and macOS tooling explained.
Read articleMQTT vs HTTP vs Direct Database Writes for IoT
Why devices that INSERT straight into a database or poll an HTTP API break at fleet scale, and why an MQTT broker feeding one ingest bridge holds up. Includes where HTTP and direct writes are still the right call.
Read articleBLE Advertising Packets Explained: AD Structures, iBeacon and Eddystone
Decode a BLE advertising packet byte by byte: the 31-byte payload, AD structures, scan response, and the iBeacon and Eddystone (UID, URL, TLM) layouts, with how to read raw advertising data on macOS.
Read articleMQTT Keep Alive Explained: Tuning It and Why Clients Disconnect
MQTT keep alive explained: the CONNECT packet field, the 1.5x timeout rule, PINGREQ/PINGRESP, how brokers detect dead clients, and how to choose the right interval for IoT devices.
Read articleEtherNet/IP RPI Explained: Requested Packet Interval and Tuning
EtherNet/IP RPI (Requested Packet Interval) explained: the timing of CIP implicit I/O, how RPI differs from the CIP connection timeout, and how to choose and tune RPI values for Allen-Bradley PLCs.
Read articleModbus 32-Bit Data Types: Register Pairs, Byte Order, Scaling
How Modbus handles 32-bit integers: two registers per value, word order (high word first vs low word first), signed vs unsigned, register pairs, and scaling examples for energy meters and drives.
Read articleVoltrus Gateway vs Kepware: Drivers, API and Licensing Compared
Kepware is a Windows OPC server licensed by driver; Voltrus Gateway is a self-hosted Rust binary with a typed gRPC API over six protocols. Platform, S7 and Allen-Bradley connectivity, licensing, and when to keep Kepware or run both.
Read articleModbus, OPC UA and EtherNet/IP in One Binary for the Edge
How one Rust binary drives six industrial protocols behind a single gRPC API, what a protocol layer should and should not own at the edge, and why a minimal stack beats a pile of services.
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