I ran npm install on a Raspberry Pi 4, the same one I’d set up as an edge gateway with OPC UA and MQTT, and watched the terminal scroll.
Node-RED, plus three protocol modules for Siemens S7 PLCs, OPC UA, and Modbus. When it finished, I counted.
IEC 62443 defines four Security Levels for industrial control systems. At the highest level — SL-4, protection against state-sponsored attacks with extensive resources — the standard calls for unidirectional data flow enforcement. Not a firewall rule. Not a software policy. Hardware-enforced, physically one-way communication.
Every factory faces the same question: how do you get sensor data from the shop floor to the systems that need it? The answer is never one protocol. It’s two — MQTT for vertical data flow to IT systems, and OPC UA for horizontal integration with SCADA and HMI on the plant floor.
In my previous post, I shared the importance of setting tag limits to prevent bad data from causing issues in SCADA systems. Now, let’s talk about another essential safeguard — clamping values.
Since WinCC Unified V17, users have been able to set upper and lower limits for tags to ensure the value stays within a defined range. This feature is essential for preventing invalid inputs and protects connected devices from unexpected inputs.
As a gas turbine controls engineer, part of my job involves working with ancillary systems such as the fire and gas system. In gas turbine packages, fire and gas systems are used to detect fires and flammable gases which are hazards to the operating environment.