Blog Archive: May 2026
35 articles published in May 2026.
Everything Voltrus published in May 2026: "Modbus RTU Troubleshooting Guide: CRC Errors, Timeouts, and Wiring", "Best Modbus Simulator in 2026: Free and Paid Tools Compared", "MQTT Sparkplug B Explained: Industrial IoT Protocol Guide (2026)". Practical guides and comparisons for engineers working with industrial automation tools, from protocol explorers to SCADA and HMI.
Modbus RTU Troubleshooting Guide: CRC Errors, Timeouts, and Wiring
Fix Modbus RTU communication errors. Step-by-step troubleshooting for CRC errors, timeouts, and wiring problems. How to read Modbus RTU frames and diagnose RS485 bus issues.
Read articleBest Modbus Simulator in 2026: Free and Paid Tools Compared
Need to test Modbus devices without hardware? Compare five Modbus simulators: Modbus Poll, Modbus Slave, diagslave, PyModSlave, and ModRSsim2. Covers macOS, Windows, Linux.
Read articleMQTT Sparkplug B Explained: Industrial IoT Protocol Guide (2026)
MQTT Sparkplug B explained for industrial automation. Understand topics, payloads, birth/death certificates, data types, and how Sparkplug B compares to basic MQTT.
Read articleBACnet vs Modbus for Building Automation (2026): Protocol Comparison
BACnet vs Modbus for building automation. Compare data models, discovery, scalability, and HVAC integration. When to use each protocol and how to test on macOS.
Read articlePLC Programming on a Mac: CODESYS Alternatives and Soft PLCs
How to program PLCs on a Mac without Windows: CODESYS alternatives, running a soft PLC, simulating logic without hardware, and what still needs a Windows VM.
Read articlePLC Programming Languages: The 5 IEC 61131-3 Languages Explained
The five IEC 61131-3 PLC languages compared, which to learn first, and when a PLC beats an Arduino-class microcontroller.
Read articleIEC 61131-3 Structured Text: A Practical PLC Programming Guide
Learn IEC 61131-3 Structured Text (ST), the modern way to program PLCs. Syntax, data types, function blocks, timers, counters, and real examples.
Read articleTwinCAT Alternative: PLC Development Without Beckhoff Lock-In (2026)
TwinCAT locks you into Beckhoff hardware and Windows. Compare alternatives: Voltrus PLC (macOS native, IEC 61131-3 ST, multi-vendor I/O), CODESYS, and OpenPLC.
Read articleSCADA Alarm Management: Best Practices for ISA-18.2 Compliance (2026)
SCADA alarm management guide. Reduce alarm floods, implement ISA-18.2 best practices, configure deadbands, and improve operator response. Metrics, rationalization, and shelving.
Read articleWhat Is Modbus? The Protocol That Runs Industrial Automation
Modbus explained for engineers: how it works, why it's still dominant after 50 years, and the difference between Modbus RTU, TCP, and ASCII.
Read articleModbus Register Types: Coils, Inputs and Holding Registers
The four Modbus data types and their function codes. How to read coils (FC01), write registers (FC06/FC16), and avoid common addressing mistakes.
Read articleRS-232 vs RS-485 vs RS-422: Serial Communication Protocols Compared
UART, RS-232, RS-485, and RS-422 explained. Distance limits, device count, noise immunity, and which serial standard your industrial equipment uses.
Read articleModbus RTU vs TCP, and the RTU to TCP Gateway
How Modbus RTU and TCP differ in speed, wiring and distance, and how an RTU to TCP gateway routes requests by unit ID, where its latency really comes from, and hardware vs software gateways.
Read articleS7 Communication Protocol Guide: Memory Areas, Addressing, and Data Types
How the Siemens S7 protocol accesses PLC memory. Data blocks, inputs, outputs, markers, timers, counters. Rack/slot addressing and data type mapping.
Read articleMQTT QoS Levels Explained: When to Use QoS 0, 1, or 2
MQTT QoS 0, 1, and 2 explained with practical examples. At-most-once, at-least-once, exactly-once delivery for IoT and industrial systems.
Read articleIndustrial Protocol Comparison: Modbus, OPC UA, MQTT, S7, DNP3, EtherNet/IP, PROFINET
How to choose between Modbus, OPC UA, MQTT, Siemens S7, DNP3, EtherNet/IP and PROFINET, with the S7 vs Modbus TCP, DNP3 vs Modbus and EtherNet/IP vs PROFINET decisions worked through.
Read articleSCADA vs HMI: What's the Difference and Do You Need Both?
The practical difference between SCADA and HMI for system integrators. When you need one, the other, or both, and why the distinction matters for your next project.
Read articleSCADA Architecture Explained: RTU, PLC, HMI, and How They Connect
SCADA architecture from field devices to the control room. RTUs, PLCs, HMIs, and how data flows from a sensor reading to a dashboard alert.
Read articleVoltrus vs Wonderware (AVEVA): Cost and Complexity Compared
Voltrus vs AVEVA Wonderware comparison for system integrators. Pricing, deployment complexity, protocol support, and when each makes sense.
Read articleConnecting Siemens PLCs Without TIA Portal: A Practical Guide
You don't need TIA Portal to monitor Siemens S7 PLCs. How to connect S7-1200 and S7-1500 directly from your SCADA using the S7 protocol.
Read articleLadder Logic vs Structured Text for SCADA Projects
Which PLC language to learn (ladder logic or Structured Text), and why SCADA configuration does not require either. Side-by-side comparison, examples, and a practical learning path.
Read articleIndustrial Dashboard Design: 12 Principles for SCADA Screens
Twelve design rules for SCADA and factory dashboards operators actually use, plus mobile design, secure remote access and locked-down kiosk-mode operator consoles.
Read articleSelf-Hosted Pastebin on Cloudflare Workers vs PrivateBin, Gist and Pastebin.com
Deploy a self-hosted pastebin on Cloudflare Workers, D1 and R2, and see how it compares to Pastebin.com, PrivateBin and GitHub Gist on data location, files, setup and cost.
Read articleHow to Share Files Between Remote Servers Without Cloud Storage
Remote server file sharing without cloud storage. Transfer logs, configs, and screenshots between isolated networks using a self-hosted pastebin. No Dropbox, no Google Drive.
Read articleBest Modbus Simulator for macOS (2026): PM5560, SMA Inverter, and More
Modbus simulator with real device templates. Simulate Schneider PM5560 power meter, SMA solar inverter, ABB analyzer on macOS. No Parallels, no Windows.
Read articleSchneider PM5560 Modbus Register Map and Simulator
Complete PM5560 Modbus register map with addresses for voltage, current, power, power factor, frequency, and energy. Includes a PM5560 simulator for macOS.
Read articleSerial Terminal for macOS: screen, minicom and CoolTerm Alternatives
Best serial terminal apps for macOS in 2026. Compare screen, minicom, CoolTerm, Serial by Decisive Tactics, and MacTools. Hex view, protocol analysis, USB-RS485.
Read articleMQTT Broker on macOS: Run One Without Homebrew or Terminal
How to run an MQTT broker on macOS without Homebrew, Terminal, or mosquitto. Native MQTT broker and client with GUI for macOS.
Read articleConnect to Siemens S7-1200/1500 from macOS without TIA Portal
Read and write S7-1200/1500 data blocks from a Mac without TIA Portal or a VM. Covers enabling PUT/GET in TIA Portal, the security trade-off, and connecting over port 102.
Read articleBLE Debugging on macOS: nRF Connect vs BLE Inspector and Other Tools
Compare nRF Connect, LightBlue, Bluetooth Explorer, CLI tools and BLE Inspector for debugging BLE peripherals on a Mac, and what a complete workflow needs.
Read articleOT Security Checklist: 15 Steps to Harden Your SCADA System
Actionable security checklist based on real OT breach analysis and IEC 62443 best practices. Default credentials, network segmentation, monitoring, and more.
Read articleFDA 21 CFR Part 11 Compliance for SCADA: What Integrators Need to Know
Pharma, food, and beverage integrators need audit trails, electronic signatures, and access controls. What CFR Part 11 actually requires from SCADA, and how to deliver it without $10K+ consulting.
Read articleSCADA Software Cost in 2026: From Free to $50K
What SCADA actually costs in 2026, from AVEVA and Ignition to free tools, the hidden time cost of open source, lifetime vs subscription math, and what a sub-$1,000 budget covers.
Read articleIgnition vs Node-RED vs Voltrus: SCADA Alternatives Compared
How Ignition, Node-RED, Voltrus, OpenSCADA and ScadaBR compare for system integrators on pricing, resource use, protocols and fit by project size.
Read articleOn-Premise vs Cloud SCADA: Air-Gapped, Edge and Raspberry Pi
Why connectivity, data sovereignty, latency, security and cost often favor local SCADA, and how to run it on a mini PC or Raspberry Pi.
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