A very common question from people coming from other cobot brands (UR, FANUC, etc.): "Why does pressing the emergency stop require restarting the entire control box? Can't I just release it and continue?"
Short answer: Yes, this is expected default behavior
The default emergency stop configuration on Fairino robots is Category 0 (STO — Safe Torque Off). This means a full power cycle of the control box is required after pressing and releasing the E-stop button. The robot will ask you to restart every time.
This is by design for safety — pressing the E-stop should be a rare, serious event. For comparison: Siemens cancer treatment machines require ~45 minutes of elaborate procedure to recover from an emergency stop.
Can the behavior be changed?
Yes. The emergency stop behavior can be configured using safety categories:
| Category 0 | Full power cycle required (default). Motors lose power immediately. |
| Category 1 | Controlled deceleration stop, then power off. Still requires restart but stops more gently. |
| Category 2 | Robot stops and holds position. Can be cleared and resumed without restarting the controller. This is what most people want for development. |
Configuration reference: manual.fairino.support — Emergency Stop
Note: One user with an FR20 reported that after changing to Category 2, they no longer need to restart the control box after E-stop. However, this may not work identically on all models/firmware versions.
Alternatives for development — avoid using E-stop entirely
During development, instead of hitting E-stop every time you need to stop quickly (e.g. when changing tools, testing movements), use these alternatives:
Option 1: WebApp Pause/Stop buttons
Use the Pause and Stop buttons in the WebApp interface. Pause = hold to stop, release to resume. Stop = permanent stop until you restart the program.
Option 2: External physical Pause/Stop buttons
Connect physical pushbuttons to the control box digital inputs (DI). Configure them to act as Pause and Stop. This gives you the same functionality as the WebApp buttons but with a physical button you can slap quickly.
The workflow: Press Pause first — the robot immediately stops moving (but you must hold the button pressed, otherwise it resumes). If you want to stop completely, then press Stop — the robot remains motionless even when all buttons are released.
Option 3: Protective Stop (recommended for integration)
Use the double channel protective input in safety category 1 or 2. This is specifically designed for integration into machine safety circuits without requiring a full power cycle.
Reference: manual.fairino.support — Protective Stop
For production environments
In production, the control box restart after E-stop is usually not a big problem because:
- E-stop should be rare (emergencies only)
- A large, convenient main switch within easy reach of the operator makes the restart quick
- Some integrators use an external relay to automate the power cycle (Category 0 E-stop → relay cuts power → relay restores power → controller boots automatically)
Known issue: "Please release the button" message persists
Some users report that after releasing the E-stop button, the message "Please release the emergency stop button" stays on screen. Solution: power cycle the controller completely (turn off, wait 5 seconds, turn on).