PLC-Ladderplc
25 posts
AI generates. The compiler validates. The human approves.
How PLC-Ladder turns plain English into IEC 61131-3 logic you can trust: the AI drafts, a strict compiler validates, and nothing ships until you approve it.
10 PLC Practice Projects You Can Build Free in Your Browser (Beginner to Advanced)
Ten PLC practice projects from beginner to advanced, all buildable free in a browser simulator: specs, hints, and the skills each one trains — no hardware.
Learn PLC Programming Free: The Complete No-Hardware Path (2026)
Learn PLC programming free with no hardware: a complete self-study path from first rung to OPC UA, using free browser tools — with milestones and timelines
Function Block Diagram Online: Draw and Simulate FBD Free in Your Browser
Build function block diagrams online free: drag standard IEC blocks, wire them, and simulate FBD logic live in the browser — no install, no license, no PLC.
How to Test an Ignition HMI Without a PLC: OPC UA Against Simulated Logic
Test an Ignition HMI without a PLC: point the gateway's OPC UA client at simulated logic, bind real tags, and verify screens before the hardware ever arrives.
PLC Online Compiler: Write, Compile and Verify IEC 61131-3 in the Browser
What a PLC online compiler checks and why it matters: types, timer instances, duplicate coils and unreachable logic — compile IEC 61131-3 free in the browser.
Ladder Diagram Maker: Draw and Export Ladder Diagrams Online Free
Draw ladder diagrams online free with a ladder diagram maker that checks your logic: clean diagrams for reports and documentation, plus live simulation.
7 Free PLC Simulators Compared (2026): Browser, Open Source and Vendor Tools
Seven free PLC simulators compared honestly in 2026: PLC-Ladder, PLC Fiddle, OpenPLC, CODESYS, Do-more Designer, CCW and TIA PLCSIM — which fits your need.
How to Test an Ignition HMI Without a PLC: OPC UA Against Simulated
Test an Ignition HMI without a PLC: point the gateway's OPC UA client at simulated logic, bind real tags, and verify screens before the hardware ever arrives.
Connect OPC UA to UaExpert and Ignition SCADA: Step-by-Step Tutorial
How to connect an OPC UA server to UaExpert and Ignition SCADA step by step: endpoints, security policies, certificates, browsing nodes and first live tags.
OPC UA for PLC Programmers: How Your Tags Get From the Controller to Everything Else
OPC UA explained for PLC programmers: what it is, how servers, nodes and subscriptions work, OPC UA vs Modbus vs OPC Classic, and what it means for your tags.
Function Block Diagram Symbols: Every Standard Block and What Its Pins Mean
Every standard FBD symbol explained pin by pin: AND, OR, NOT, TON, TOF, TP, CTU, CTD, R_TRIG, SR/RS, MOVE with EN/ENO and comparators — with ST equivalents.
Structured Text Examples: 10 Real PLC Programs Explained Line by Line
Ten structured text programming examples for PLC: start/stop, timers, counters, CASE state machines, FOR loops, scaling and alarms — explained line by line.
FBD vs Ladder Logic: Which PLC Language for Which Job
FBD vs ladder logic compared honestly: same underlying logic, different readability. Which language fits interlocks, analog, sequences — and when to mix.
Allen-Bradley Ladder Logic: XIC, XIO, OTE and How Rockwell's Rungs Differ from IEC
Allen-Bradley ladder logic explained: XIC, XIO, OTE, OTL/OTU, ONS, TON and CTU in Rockwell terms, mapped to IEC 61131-3 — for Studio 5000 and RSLogix users.
Function Block Diagram Symbols: Every Standard Block and What Its Pins Mean
A reference to FBD symbols in IEC 61131-3: AND, OR, TON, TOF, TP, CTU, CTD, R_TRIG, SR, RS, comparators and math blocks, with every pin explained.
Catching Unsafe PLC Logic Before Commissioning: Find Ambiguous Control Behaviour Early
How to catch ambiguous and unsafe PLC control behaviour before commissioning: the six bug classes, simulation-first testing, and structured test injection.
Plain English to PLC Code: How Natural Language Becomes Verified Ladder and FBD Logic
How plain English becomes verified ladder and function block logic: the pipeline from written spec to IEC 61131-3 code, and why verification is the hard part.
Most commissioning rework starts as an unread assumption
Why control logic fails at FAT, and how to surface ambiguity and unsafe behaviour while it is still cheap — before the panel is powered.
PLC Counters Explained: CTU, CTD and Why Edge Detection Matters
PLC counters explained: CTU, CTD and CTUD pin by pin, plus the edge-detection trap that makes one button press count 400 times — and how R_TRIG fixes it.
FBD Programming Examples: 8 Real Circuits Explained Block by Block
Eight FBD programming examples explained block by block: seal-in, timers, flasher, counter, comparator, hysteresis alarm, edge detection and scaling.
PLC Timers Explained: TON, TOF and TP with Ladder and FBD Examples
PLC timers explained: how TON, TOF and TP function blocks work, their IN, PT, Q and ET pins, and real ladder and FBD examples for each timer type.
Structured Text (ST) PLC Programming: Syntax and Examples
Structured Text (ST) for PLCs: variables, IF/CASE, loops, timers and function blocks, with real examples and when to choose ST over ladder.
Ladder Logic for Beginners: Rungs, Contacts, Coils and the Scan Cycle
Ladder logic explained for beginners: rungs, contacts, coils, the PLC scan cycle, series AND, parallel OR, and the seal-in circuit with examples.
Function Block Diagram (FBD) PLC Tutorial, with Examples
Learn Function Block Diagram (FBD) PLC programming step by step: blocks, pins, wires, execution order and when FBD beats ladder logic, with worked examples.