Blog Archive: July 2026
8 articles published in July 2026.
Everything Voltrus published in July 2026: "Modbus Addressing: PLC Address vs Protocol Address (Off-By-One)", "Secure Remote Access to PLC Networks: WireGuard vs VPN", "BACnet Objects and Properties: The Object Model Explained". Practical guides and comparisons for engineers working with industrial automation tools, from protocol explorers to SCADA and HMI.
Modbus Addressing: PLC Address vs Protocol Address (Off-By-One)
Why Modbus holding register 40001 is protocol address 0. The PLC address vs protocol address off-by-one confusion, the four address ranges, and how to convert between them.
Read articleSecure Remote Access to PLC Networks: WireGuard vs VPN
Outbound-only WireGuard access to PLC subnets with a self-hosted Headscale control plane: threat model, deployment steps, ACL design, comparison with IPsec and OpenVPN, and IEC 62443 and NIS2 alignment.
Read articleBACnet Objects and Properties: The Object Model Explained
BACnet models every data point as an object with typed properties (Present-Value, Units, Status-Flags). This self-description enables discovery (no external register map needed).
Read articleOPC-UA vs MQTT for Industrial IoT: Which Should You Choose
OPC-UA for rich plant-floor integration and SCADA; MQTT for lightweight multi-site telemetry. Data models, security, bandwidth, and when each protocol wins.
Read articleSCADA for Water and Wastewater: A System Integrator Guide
Remote pump stations, radio/cellular telemetry, DNP3 and Modbus, alarm management for unattended sites, and why lightweight self-hosted SCADA fits thin utility budgets.
Read articleSCADA Historian: Data Logging and Trend Analysis That Actually Helps
A historian stores full-resolution, time-stamped process data, the foundation for troubleshooting, predictive maintenance, and compliance. Build vs buy, and retention strategy.
Read articleModbus TCP Security Risks: Why It Is Not Safe and How to Protect It
Modbus TCP has no authentication, encryption, or integrity: anyone on the network can read and write every register. Segment, firewall, and tunnel it; never expose TCP/502.
Read articlePostgres CLI Tools vs pgAdmin: When the Terminal Wins
pgAdmin is a heavy web UI that is painful over SSH. Terminal Postgres browsers like PostgresTUI start instantly, work natively over SSH, and stay out of your way for quick queries.
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