Input devices supply a voltage signal TO the PLC — they are sensing/triggering devices.

• Limit switches
• Push buttons

Output devices receive a signal FROM the PLC — they do work.

• Indicator lamps
• Motor contactors

• Bit = 1 (TRUE) → contact CLOSES → power passes
• Bit = 0 (FALSE) → contact stays open → no power
• Used for start buttons and seal-in (latch) contacts

• Bit = 0 (FALSE) → contact CLOSED → power passes
• Bit = 1 (TRUE) → contact OPENS → power blocked
• Used for stop buttons and safety interlocks

Ladder logic reads like an electrical circuit:

• Left rail = power supply (+)
• Right rail = return (−)
• Rung = path from left to right rail

• Moves the TCP in a straight line from start to end point
• Path is predictable — useful when obstacles are nearby
• Used for approach and depart moves in pick-and-place

• Each joint moves independently to reach the target
• TCP path can be curved or unexpected
• Faster, but less predictable — use only in open space

• Robot decelerates to zero velocity and fully stops at the point
• Use Fine for precision positions: pick/place locations, critical waypoints

• CNT 0 — blends close to the point (smallest arc, nearly stops)
• CNT 100 — largest blend arc; robot swings farthest from the point
• Robot never fully stops — creates smoother, faster transitions

• A momentary input (e.g., push button) energizes the output coil
• A normally-open contact of that same output is wired in parallel with the input
• Once the output energizes, it "seals itself on" through its own contact
• A separate stop input (normally-closed contact in series) breaks the latch

• Models real-world behavior: a motor should stay ON after you press start
• Avoids holding a button continuously
• Mirrors industrial conveyor, pump, and motor control logic

1. Enabling rung goes TRUE → timer begins counting
2. When accumulated value reaches preset → timer done bit (DN) energizes
3. If enabling rung goes FALSE before preset → timer resets to zero

• Preset (PT): Target time (e.g., 5 seconds)
• Accumulated (ET): Current elapsed time
• Done bit (DN/Q): Becomes TRUE when ET ≥ PT

• Used for programming and testing — jogging, teaching points, stepping through programs
• Enable function (open rectangle icon, top right) must be toggled ON
• Run programs step-by-step using the Play Tab → Step → drag Run slider
• Required any time you enter the work cell

• Used for running completed programs continuously
• TP is disabled; robot runs from Play menu (Run slider FWD)
• Operator must be outside the work cell
• Only use after fully verifying all points in Teach (Step) mode first

Payload is the total mass the robot must support at its end of arm — including the end effector (e.g., gripper) and any object being carried.

• Motion accuracy: The controller uses payload to calculate correct speed, acceleration, and motor torque — wrong payload leads to overshoot or sluggish motion
• Force sensing: Cobots use payload to calibrate collision detection — if payload is wrong, the robot may not stop when it should (or may stop unnecessarily)
• Mechanical safety: Exceeding the rated payload can overload joints and damage the robot

• Payload changes mid-program: gripper only (moving to pick) vs. gripper + object (carrying)
• The payload setting must be updated at the right point in the sequence so the robot always has accurate inertia information

[Stop_In NC] ─── [Start_In NO] ──────────────( Lamp_Out )
                       │
               [Lamp_Out NO] ────────────────
                    

• Add a normally-open contact of the Lamp Output in parallel with the Start Button contact
• Once the lamp energizes, it "seals itself on" through its own contact
• A normally-closed Reset Button contact in series breaks the latch

• Pressing Start_In energizes Motor_Out
• Motor_Out NO in parallel seals the latch — motor stays on after Start is released
• Pressing Stop_In opens the NC contact, cutting power and turning the motor off

• Motor_Out NO enables Timer1 (TON, preset = 5 s)
• The timer accumulates only while the motor is running; resets if motor stops before 5 s

• When Timer1 reaches its preset, the DN (done) bit goes TRUE
• Alarm_Out energizes — e.g., a warning light or buzzer turns on
• Alarm stays on as long as the motor has been running ≥ 5 s; turns off when motor stops

In Cartesian (World) jogging, X, Y, and Z refer to axes of a fixed coordinate frame attached to the robot's base — not to the tool or the flange.

• It didn't — +X in World frame is always the same direction regardless of how the arm is oriented
• The robot's joints move differently to achieve the same World-frame motion, which can make it look unexpected
• If the student was jogging in Tool frame instead, then rotating the flange would change which real-world direction +X points

• World/Cartesian frame: Fixed to the robot base — X, Y, Z always point the same way
• Tool frame: Fixed to the end effector — axes move with the tool as it rotates
• Choosing the right frame for jogging matters: World frame is predictable; Tool frame is useful when you want to move relative to the tool tip

Problem: The robot is using Joint motion, which optimizes each joint independently and can produce unexpected TCP paths.

1. Switch transit motion to Linear (L) — moves the TCP in a straight line; change Motion Type in the code block Details tab
2. Add an intermediate waypoint — teach a safe via-point between pick and place to guide the path
3. Reduce approach height so the robot lifts less before traveling horizontally
4. Reduce override speed while testing to catch unexpected paths before they cause damage