Predictable PLC State Machines: A Practical Pattern That Scales

Modern PLC projects suffer when control logic is scattered across rungs, hidden in timer branches, or tightly coupled to raw I/O. The result is brittle behavior, difficult commissioning, and painful offline testing. The approach below is a simple, repeatable pattern for building state-driven modules that stay deterministic, testable, and vendor‑friendly. It divides each routine into clear sections—Inputs → Commands → Interlocks → Permissives → State & Transitions → Status → Control Resources → Outputs—and enforces one rule above all: states govern state; device control happens only in Outputs. Whether you write in ST or Ladder, this structure keeps behavior predictable and easy to review. ...

September 8, 2025 · 9 min · Jonathan Skinner

How To Change The IP Address On A Panelview HMI

Access The Factorytalk ME Configuration Menu If a project is already loaded on the HMI, the project must have a button to go to the HMI configuration. If there is no project, the configuration menu should load automatically. Setup IP Address Tap Terminal Settings and select Network and Communications and tap Enter Select Network Connections and tap Enter Select Network Adaptors and tap Enter Tap IP Address Enter IP Address, Subnet, and Gateway Tap OK (F7) at the bottom of the window. I dialog will appear letting you know the device needs reset to take effect. Press Ok. Back out of the menus until you are at the main menu. Reset the device by pressing the Reset button. The device will restart.

December 14, 2021 · 1 min · Jonathan Skinner