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Reference · Robotics

Robot Programming Languages Explained

Most industrial robots are programmed in a vendor-specific text language — URScript, RAPID, KRL, FANUC TP, INFORM — paired with a graphical teach pendant. The languages differ, but the concepts (frames, TCP, joint vs linear moves, waypoints, I/O) are universal. This guide explains each language accurately, then helps you pick which to learn first.

A close-up of a UR-style six-axis robot arm in the browser-based robot simulator, showing its jointed links and gripper, illustrating how robot programming languages map text commands to motion.

The big picture

Different languages, one shared model

There is no single "robot language". Every major manufacturer ships its own controller with its own programming language, and a program written for one brand will not run on another. But underneath the differing syntax, every six-axis industrial arm and collaborative robot shares the same handful of ideas. Learn these once and changing vendors becomes a matter of new syntax, not new concepts.

Diagram comparing robot programming languages by vendor — URScript, RAPID, KRL and FANUC TP — each expressing the same joint move and linear move with different syntaxFour robot programming languages — URScript, ABB RAPID, KUKA KRL and FANUC TP — each expressing the same joint move, showing the concepts transfer across vendors.same move — four dialectsURScriptUniversal Robotsmovej(p1)RAPIDABBMoveJ p1KRLKUKAPTP P1TPFANUCJ P[1]
Four vendor languages, one shared motion model: the concepts transfer even though the syntax does not.
Diagram of robot coordinate frames and the tool center point: base frame, tool frame and TCP, the shared model behind every robot programming languageTwo coordinate frames — a fixed base frame and a tool centre point (TCP) frame — each drawn with red X, green Y, and blue Z axis arrows.ZXYBASEZXYTCP
Frames & TCP
Diagram of joint versus linear robot moves: a curved joint-space path versus a straight Cartesian line, the distinction every robot language expresses as movej/movel, PTP/LIN or J/LTwo tool paths between the same two points: a curved joint move (movej) in cyan and a straight linear move (movel) in amber.ABmovej — joint arcmovel — straight line
Joint vs linear moves
Diagram of robot digital I/O: setting a digital output to fire a gripper and reading an input, the I/O model every robot programming language sharesA two-finger robot gripper shown open (DO=0) and closed on a part (DO=1), controlled by a digital output signal.OPENDO = 0set DOCLOSEDpartDO = 1DO active
Digital I/O

Frames & the tool centre point (TCP)

Every program works in coordinate frames — a base frame, a tool frame, and often work-object frames. The TCP is the point on the tool the robot actually controls and moves. Define the TCP correctly and your moves land where you mean them to; get it wrong and every position is off.

Joint moves vs linear moves

A joint move interpolates each axis from its current angle to the target — fast and efficient, but the tool follows a curved path. A linear move drives the TCP in a straight Cartesian line. Every vendor has both: movej/movel, MoveJ/MoveL, PTP/LIN, J/L, MOVJ/MOVL.

Waypoints & teaching

Positions are usually taught: you jog the arm to a pose with the pendant and save it as a waypoint rather than typing coordinates. A program is then a sequence of moves between waypoints, often with a blend so the arm rounds corners smoothly instead of stopping at each point.

Digital I/O

Robots talk to the rest of the cell through digital inputs and outputs — firing a gripper, signalling a conveyor, reading a part-present sensor. Every language has commands to set an output and read an input, and most real programs are mostly motion plus I/O sequencing.

Language by language

The major robot programming languages

Here is each major language, what it looks like, and where it is used — with links to a full guide for each vendor.

URScript — Universal Robots

URScript is the text language built into every UR controller, with a Python-like syntax. Motion is movej (joint), movel (linear) and movep (constant-speed process paths); set_digital_out drives I/O like a gripper; set_tcp and set_payload configure the tool. It is widely considered the friendliest robot language, and every graphical PolyScope program compiles down to it. This is the language our simulator teaches because the concepts transfer to every other vendor.

movej(p_home, a=1.4, v=1.0)      # joint move
movel(p_pick, a=0.5, v=0.1)      # linear move down
set_digital_out(0, True)         # close gripper

Full guides: Universal Robots programming · Learn URScript

RAPID — ABB

RAPID is ABB's structured text language, edited on the FlexPendant or in RobotStudio. Programs are organised into modules and procedures (PROC … ENDPROC). Motion instructions are MoveJ (joint), MoveL (linear) and MoveC (circular), each taking a target, a speed (v1000) and a zone/blend (z50, or fine to stop exactly). RAPID is common in welding, assembly and material handling.

MoveJ pHome, v1000, z50, tool0;
MoveL pPick, v200, fine, tool0;
SetDO doGripper, 1;

Full guide: ABB robot programming

KRL — KUKA Robot Language

KRL is KUKA's text language, edited on the smartPAD pendant or in KUKA.OfficeLite / WorkVisual. Its motion commands are PTP (point-to-point joint move), LIN (linear) and CIRC (circular). KRL uses $-prefixed system variables for things like I/O ($OUT[1]) and speed, and structures programs with DEF … END. It is heavily used in automotive, heavy handling and machining.

PTP HOME
LIN P_pick
$OUT[1] = TRUE   ; close gripper

Full guide: KUKA robot programming

TP & KAREL — FANUC

FANUC robots are programmed two ways. TP (Teach Pendant) is the everyday language: you build a numbered list of instructions on the pendant, where J means a joint move and L a linear move, each with a speed and a termination type (FINE or CNT for blending). KAREL is FANUC's Pascal-like text language for more complex logic, data handling and background tasks. Most line work is TP; KAREL is used where TP runs out of expressiveness. FANUC is dominant in high-volume automotive and general industry.

J P[1] 100% FINE
L P[2] 200mm/sec CNT50
DO[1] = ON   ! close gripper (TP)

Full guide: FANUC robot programming

INFORM — Yaskawa Motoman

INFORM is the language for Yaskawa Motoman robots, written as an instruction list on the pendant. Motion instructions are MOVJ (joint move) and MOVL (linear move), each with a speed (velocity for joint, mm/s for linear), plus MOVC for circular paths. I/O is handled with instructions like DOUT. Yaskawa is especially strong in arc welding, handling and packaging.

MOVJ VJ=50.00
MOVL V=138
DOUT OT#(1) ON   ; close gripper

Full guide: Yaskawa robot programming

VAL / VAL3 — Stäubli

VAL began as the language of the early Unimation/PUMA robots and is one of the original robot languages. Its modern descendant, VAL3, is the structured text language used on Stäubli robots, with a syntax closer to a general-purpose programming language (typed variables, functions, libraries). Stäubli arms are known for precision and clean-room duty, so VAL3 shows up in high-accuracy assembly, life-sciences and cleanroom applications.

Graphical & flow languages — cobots

Many collaborative robots are programmed without typing code at all. UR's PolyScope builds a program tree of nodes; Doosan's DART-Studio uses block-based programming; Omron's TMflow uses a flowchart where each node is a move, an I/O action or a logic branch. These visual environments lower the barrier so non-programmers can deploy a cobot, while still exposing the same underlying concepts — waypoints, joint vs linear moves, TCP and I/O.

Full guides: Doosan cobot programming · Omron robot programming

ROS & ROS2 — Python / C++

ROS (the Robot Operating System) and its successor ROS2 are not a vendor language but the dominant framework for robotics research and complex integration. You write nodes in Python or C++ that pass messages over topics and services, and use packages like MoveIt for motion planning across many robot brands. ROS is the standard in research labs and multi-robot or vision-heavy systems; on a single arm running a production line, the vendor language is usually what actually executes on the controller.

Side by side

The same robot task in every language

The clearest way to see that the concepts transfer is to write the same three steps — a fast joint move to a home pose, a straight linear move down onto a part, and closing a gripper — in each vendor language. Notice how the keywords change but the structure is identical.

StepURScript (UR)RAPID (ABB)KRL (KUKA)TP (FANUC)INFORM (Yaskawa)
Joint move homemovej(home, a=1.4, v=1.0)MoveJ pHome, v1000, z50, tool0;PTP HOMEJ P[1] 100% FINEMOVJ VJ=50.00
Linear move downmovel(pick, a=0.5, v=0.1)MoveL pPick, v200, fine, tool0;LIN P_pickL P[2] 200mm/sec FINEMOVL V=138
Close gripper (DO)set_digital_out(0, True)SetDO doGripper, 1;$OUT[1] = TRUEDO[1] = ONDOUT OT#(1) ON

Every row is the same idea in five syntaxes. Learn the idea once — on URScript, the friendliest of them — and reading the others becomes a translation exercise rather than relearning robotics.

Diagram of how a robot programming language command becomes motion: a move instruction is parsed, inverse kinematics solves the joint angles, the trajectory is planned, and the arm moves — the same pipeline behind every vendor languageThree lines of URScript — movej, movel and set_digital_out — each mapped by an arrow to the corresponding motion on the robot arm.program.urpmovej(p1)movel(p2)set_digital_out(0,True)
Whatever the syntax, a move command becomes motion the same way: parse → inverse kinematics → plan → move.

Which should I learn first?

Learn the fundamentals on URScript, then specialize

With several incompatible languages it is tempting to ask which one to memorise. The better question is which one teaches the concepts fastest — because frames, TCP, joint vs linear moves, waypoints and I/O are the same everywhere, and that is what actually transfers between vendors.

URScript is the best place to start. The syntax is approachable, the motion model is the same model every other vendor uses, and you can write and run it in a browser with no hardware. Once those fundamentals are solid, picking up RAPID, KRL, FANUC TP or INFORM is mostly a matter of new keywords. If your path is research or multi-robot integration rather than a single production arm, learn Python alongside it for ROS.

That is exactly how our course is built: you write real URScript on a simulated arm, learn the universal concepts by doing, and finish with a graded capstone — so the skill transfers to whatever brand you meet on the job.

At a glance

Robot programming languages compared

LanguageVendorStyleWhere used
URScriptUniversal RobotsText (Python-like) + PolyScope flowCobot cells, pick-and-place, machine tending
RAPIDABBText + FlexPendantWelding, assembly, material handling
KRLKUKAText + smartPADAutomotive, heavy handling, machining
TP / KARELFANUCTeach-pendant instructions + Pascal-like textHigh-volume automotive and general industry
INFORMYaskawa MotomanTeach-pendant instruction listArc welding, handling, packaging
VAL3StäubliText (structured)Precision assembly, cleanroom, life sciences
DART / TMflowDoosan / OmronGraphical block / flowchartCobot deployment by non-programmers
Python / C++ (ROS)Open-source / multi-vendorGeneral-purpose code + frameworkResearch, integration, multi-robot systems

Keep learning

Per-vendor guides & the course

Questions

Robot programming languages FAQ

There is no single language — most industrial robots use a vendor-specific text language paired with a graphical teach pendant. Universal Robots use URScript, ABB uses RAPID, KUKA uses KRL, FANUC uses TP plus KAREL, and Yaskawa Motoman uses INFORM. The languages look different on the surface, but they all express the same ideas: coordinate frames, a tool center point (TCP), joint moves versus linear moves, taught waypoints, and digital I/O. Outside the vendor world, ROS/ROS2 (programmed in Python or C++) is the dominant framework for research and multi-robot integration.

Pick a language by writing real code.

Start with URScript — the friendliest robot language — on a simulated arm in your browser. The concepts transfer to every vendor, and the first lessons are free.

Technical reference and worked-example guide

Robot programming languages: field reference

Direct answer

The reader can map vendor syntax to shared motion, frame, I/O, control-flow and recovery concepts without claiming direct portability.

Written for automation learners comparing URScript, RAPID, KRL, FANUC TP or KAREL, INFORM and cobot scripting concepts.

System map / 02

NODE 01observable

Definition

Vendor, controller, language form, motion model, frame model, I/O and deployment context.

NODE 02observable

Signal path

Shared intent—move, wait, set output, call routine, handle state—to each platform syntax and runtime.

NODE 03observable

Worked example

One small pick-and-place expressed as language-neutral pseudocode before vendor translation.

NODE 04observable

Limits

Units, pose representation, blending, interrupts, error handling, options and controller generations.

NODE 05observable

Common mistake

A syntax, frame, motion, I/O or restart assumption exposed during translation.

NODE 06observable

Verification

The translated program reviewed in official documentation and tested under supervised target conditions.

Continue the signal path / 08

Industrial robotics path

Progress from motion concepts to a complete cell sequence

Practice coordinates and commands, connect the robot handshake to PLC state, then validate safety and vendor-specific behavior in the correct tools.