PLC Simulator
IEC 61131-3Allen-BradleySiemens STL+ 6 more dialects

PLC Dialect Cheatsheet

The same Button to Light, Seal-In (Motor Start/Stop), AND Gate, OR Gate, and TON On-Delay programs written in 9 PLC dialects. Click any cell to copy — no account required.

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Dialect comparison matrix — 5 programs in 9 dialects

ProgramIEC 61131-3Allen-BradleySiemens STL
Button to LightA momentary push-button directly energises an output coil. The simplest possible rung.boolean
VAR
  BTN   AT %I0.0 : BOOL;
  LIGHT AT %Q0.0 : BOOL;
END_VAR

| BTN | := LIGHT ;
Open in editor
TAG BTN   I:0/0 BOOL
TAG LIGHT O:0/0 BOOL

XIC BTN OTE LIGHT
Open in editor
VAR
  BTN   AT %I0.0 : BOOL;
  LIGHT AT %Q0.0 : BOOL;
END_VAR

      A     BTN
      =     LIGHT
Open in editor
Seal-In (Motor Start/Stop)Classic 3-wire motor control: START latches the motor output via its own feedback contact; STOP (NC) breaks the seal.boolean
VAR
  START AT %I0.0 : BOOL;
  STOP  AT %I0.1 : BOOL;
  MOTOR AT %Q0.0 : BOOL;
END_VAR

| START OR MOTOR AND /STOP | := MOTOR ;
Open in editor
TAG START I:0/0 BOOL
TAG STOP  I:0/1 BOOL
TAG MOTOR O:0/0 BOOL

XIC START OR XIC MOTOR AND XIO STOP OTE MOTOR
Open in editor
VAR
  START AT %I0.0 : BOOL;
  STOP  AT %I0.1 : BOOL;
  MOTOR AT %Q0.0 : BOOL;
END_VAR

      A     START
      O     MOTOR
      AN    STOP
      =     MOTOR
Open in editor
AND GateOutput energises only when both inputs are simultaneously active — the fundamental series rung.boolean
VAR
  A    AT %I0.0 : BOOL;
  B    AT %I0.1 : BOOL;
  OUT1 AT %Q0.0 : BOOL;
END_VAR

| A AND B | := OUT1 ;
Open in editor
TAG A    I:0/0 BOOL
TAG B    I:0/1 BOOL
TAG OUT1 O:0/0 BOOL

XIC A AND XIC B OTE OUT1
Open in editor
VAR
  A    AT %I0.0 : BOOL;
  B    AT %I0.1 : BOOL;
  OUT1 AT %Q0.0 : BOOL;
END_VAR

      A     A
      A     B
      =     OUT1
Open in editor
OR GateOutput energises when either input is active — the fundamental parallel rung.boolean
VAR
  A    AT %I0.0 : BOOL;
  B    AT %I0.1 : BOOL;
  OUT1 AT %Q0.0 : BOOL;
END_VAR

| A OR B | := OUT1 ;
Open in editor
TAG A    I:0/0 BOOL
TAG B    I:0/1 BOOL
TAG OUT1 O:0/0 BOOL

XIC A OR XIC B OTE OUT1
Open in editor
VAR
  A    AT %I0.0 : BOOL;
  B    AT %I0.1 : BOOL;
  OUT1 AT %Q0.0 : BOOL;
END_VAR

      A     A
      O     B
      =     OUT1
Open in editor
TON On-DelayOutput turns on after the start input has been active. IEC/AB show a real TON timer block; other dialects show an equivalent latch pattern.timer
VAR
  Start : BOOL;
  T1    : TON;
  Done  : BOOL;
END_VAR

T1(IN := Start, PT := T#3s);
| T1.Q | := Done ;
Open in editor
TAG Start I:0/0 BOOL
TAG T1    TON

XIC Start TON T1 PRE:3000
Open in editor
VAR
  Start AT %I0.0 : BOOL;
  Latch AT %Q0.1 : BOOL;
  Done  AT %Q0.0 : BOOL;
END_VAR

      A     Start
      O     Latch
      =     Latch

      A     Latch
      =     Done
Open in editor

About these PLC dialects

IEC 61131-3 Ladder Logic

The international standard that unifies PLC programming across vendors. Uses VAR blocks and symbolic addressing. Widely supported by Codesys, Siemens TIA Portal (LD), and most modern PLCs.

Allen-Bradley RSLogix / Logix5000

Rockwell Automation's instruction set uses XIC, XIO, OTE mnemonics and file-based addresses (I:0/0). Powers the MicroLogix, SLC-500, and ControlLogix families.

Siemens STL (Statement List)

Step 7 / TIA Portal's low-level text language. Boolean stack instructions:A (AND), O (OR), = (coil). Often called "Siemens ladder logic" by practitioners.

Mitsubishi GX Works / MELSEC

Uses LD, AND, OR, OUT with native X/Y/M device addressing. Dominant in Japanese automotive and semiconductor manufacturing.

Omron CX-Programmer

Similar mnemonics to IEC IL but with two-token negation:LD NOT, AND NOT, OR NOT. Channel-based addressing (e.g. 0.00).

Delta DVP / WPLSoft

Popular in cost-sensitive OEM markets. Uses octal-group addressing (X0–X7 = first 8 inputs). ANI /ORI for normally-closed contacts instead of separate NC tokens.

KEYENCE KV / KV STUDIO

A tested learning subset using R, MR, and DM devices with KV-style contact, coil, timer, counter, and arithmetic mnemonics.

Why compare PLC dialects side by side?

Industrial automation sites often run multiple PLC brands — an Allen-Bradley ControlLogix on the packaging line, a Siemens S7 on the press, Mitsubishi on the conveyor. Technicians who can read and translate between dialects are far more flexible and valuable. This free reference shows the same logic in each dialect so you can spot the patterns quickly: seal-in in AB looks like XIC START OR XIC MOTOR AND XIO STOP OTE MOTOR; in Siemens it is A START / O MOTOR / AN STOP / = MOTOR. Same concept, different syntax.

All programs on this page are live — you can open them in the Open in editor links or copy the code and paste it into the simulator's editor to run it against real machine scenarios.

IEC 61131-3 lessons — start from scratchAllen-Bradley PLC simulatorSiemens PLC simulatorPro access — all 9 dialects, all scenarios

Competency and practice field guide

PLC dialect learning pathway: practice plan

Direct answer

The learner can express a neutral behavior contract, identify platform-owned state and verify the translated behavior at exact boundaries.

Written for pLC learners moving between IEC concepts and Allen-Bradley, Siemens, Mitsubishi, Omron or Delta conventions without memorizing isolated mnemonics.

a controls engineer comparing generic PLC racks, remote I/O, industrial switching and protocol evidence in a platform lab while studying structured cross-vendor PLC dialect learning
System map / 02

NODE 01observable

Scope

Source and target controller, engineering version, program organization, task or scan model, tag or device model, instructions, instances, data types, time and restart behavior.

NODE 02observable

Signal path

Machine requirement through neutral state-and-transition contract, source implementation, target implementation, observed I/O and physical result.

NODE 03observable

Baseline practice

The same start-stop, timer, counter and edge cases explained and reproduced in two selected dialects.

NODE 04observable

Edge cases

First scan, retained data, skipped calls, task-period change, time conversion, overflow, online edit, download and power return.

NODE 05observable

Fault practice

A terminology, address, instance, parameter, scan, timing, retention, data-type or workflow mismatch.

NODE 06observable

Transfer to the job

Each transferred case compiled and regression-tested in the current official target environment.

Answer surface / 07

Which PLC dialect should I learn first?

Learn one platform well enough to explain I/O, scan, state, timers and diagnostics, while writing vendor-neutral behavior contracts that can be transferred later.

Are PLC dialects interchangeable?

No. Common control intent transfers, but names, parameters, instance storage, task execution, data types, reset and restart behavior can differ.

PLC dialect transfer path

Keep the control pattern while the syntax changes

Compare address families and mnemonics around the same machine task, then validate the final project in the target vendor tool.