FANUC Robot Integration and System Run-Off

FANUC Robot Integration and System Run-Off

Why This Lesson Matters

A robot cell is only as good as its integration. A robot that moves precisely but cannot talk to the PLC, or that lacks proper safeguarding, is not a production-ready system. In this capstone lab you bring together every skill from the program — frames, TP programming, I/O handshaking, PLC logic, safety standards, and structured troubleshooting — and prove the system works through a witnessed run-off.

---

Step 1: Safeguarding the Cell (ANSI/RIA R15.06 / ISO 10218)

Before powering the robot, confirm the cell meets ANSI/RIA R15.06. The standard requires that no person can reach a hazardous zone during automatic operation. Acceptable safeguards include a perimeter fence with a safety-rated interlocked gate, a light curtain, or a safety-rated monitored stop system. Every entry point must interrupt robot motion when opened or crossed. Check that the safety relay or safety PLC monitors the gate switch and drops robot enable if the gate opens. Do not bypass any interlock — even temporarily — without a written procedure and supervisor approval.

Post the ANSI/RIA R15.06 summary card at the cell entry. Verify emergency-stop buttons are accessible from outside the fence, functional, and latching.

---

Step 2: Establishing Frames

World frame is the robot's built-in reference. You normally do not change it, but you must understand its orientation before teaching other frames.

User frame defines a coordinate system tied to your work fixture. Teaching a user frame means the robot's position readout is relative to the fixture, not the robot base. This makes program positions portable — if the fixture moves slightly, you update the frame rather than reteach every point. Use the three-point method (origin, X-direction point, Y-direction point) on the teach pendant under SETUP > Frames > User Frame.

Tool frame (TCP — Tool Center Point) tells the robot where the tip of its tool is relative to the faceplate. Calibrate it using the three-point or six-point procedure: jog to a fixed reference pin from three (or six) different approach angles, and the controller calculates the TCP offset. After calibration, jog the robot in tool coordinates and confirm the TCP stays on the reference point while the wrist rotates. Measure repeatability at three taught reference points using a dial indicator or ruler; target is ±2 mm or better.

Document every frame — position coordinates and rotation values — in your project log before writing a single program line.

---

Step 3: Writing the TP Program (HandlingTool)

Open a new program in the teach pendant. Use HandlingTool motion instructions. Key rules:

• Motion type: Use FINE termination for pick and place points where accuracy matters. Use CNT (continuous) for via points where speed matters and exact stop is not needed.
• Speed: Set conservative overrides initially (10–30%). Increase speed only after collision-free runs are confirmed.
• Teach at least six positions: home, approach, pick, retract, place approach, place, retract to home.
• I/O instructions: Use `WAIT DI[n]=ON` to pause until the PLC signals part-present. Use `DO[n]=ON` to signal the PLC when the robot cycle is complete. These two instructions form the handshake.
• Fault routine: Include a `CALL` to a fault sub-program that sets an output to the HMI and holds position without damaging motion.

Before running on the live robot, load the program into ROBOGUIDE and simulate the full cycle. Check for joint-limit warnings and collisions in the simulation. Correct any issues offline first.

When running on the live robot, follow this sequence:

1. T1 mode (manual reduced speed, ≤250 mm/s at the TCP) with a trained safety observer outside the fence holding the enable device.

2. Step through each line individually.

3. Run the full program in T1 until three clean cycles are complete.

4. Switch to Automatic mode only after T1 verification. No person may be inside the fence during automatic operation.

---

Step 4: PLC I/O Handshaking

The PLC and robot exchange signals through discrete wiring or EtherNet/IP. Map robot outputs (DO) to PLC inputs and robot inputs (DI) to PLC outputs in the I/O configuration screen on the teach pendant. Confirm signal states using the PLC's online data monitor and the robot's I/O status screen simultaneously. A common handshake sequence:

1. PLC sets "Part Present" output → Robot DI goes ON → Robot starts pick sequence.

2. Robot completes pick → Robot DO "Cycle Complete" goes ON → PLC acknowledges and advances conveyor.

3. Robot sees DI "Clear to Place" → executes place move → signals done.

Log every signal name, address, and verified state in your project log.

---

Step 5: The Ten-Cycle Run-Off

Start from the defined home state with the cell clear and gates closed. Run ten consecutive automatic cycles. The observer records cycle time for each cycle and notes any faults. All ten must complete without fault. If a fault occurs, correct it, reset to home, and restart the count from zero.

Every time any person needs to enter the cell — for adjustment, measurement, or seeded-fault work — apply LOTO per OSHA 29 CFR 1910.147: de-energize the robot controller, apply your personal lock, verify absence of stored energy (servo capacitors discharge; follow controller manual guidance), then enter. Remove the lock only after exiting and confirming the cell is clear.

---

Step 6: Seeded-Fault Troubleshooting

After a successful run-off, the instructor introduces three seeded faults — one electrical, one PLC/program, one robot/mechanical. For each fault:

1. Observe the symptom.

2. State the probable cause.

3. Perform a test to confirm or rule out the cause (use a multimeter, PLC data monitor, or robot alarm log).

4. Apply the corrective action.

5. Log all four items in the troubleshooting log.

All three faults must be diagnosed and resolved within a combined 45-minute window.

---

Safety Reminders

• NFPA 70E: Verify absence of voltage with a CAT-rated meter before touching any electrical connection.
• OSHA 1910.212: Machine guarding must be in place before any automatic run.
• ANSI/RIA R15.06: The fence interlock is a life-safety device — never jumper it.
• Wear appropriate PPE: safety glasses inside the lab at all times; steel-toed footwear near the robot cell.