Safety Functions

The robot system has the following safety functions. Because of their particular importance for safety, always make sure that they are working before using the robot system.

Controller Safety Function standard functions:

• Safe Torque OFF (STO)
  A signal input from the Robot Controller opens a relay to cut off the power supply to the motors and stop the robot. This is a safe state for the Robot Controller.
  STO is operated indirectly from an emergency stop or protective stop. It will also operate when the Safety board detects abnormalities. It cannot operate directly.

• Emergency Stop
  This function allows the robot to perform an emergency stop by a signal input from a safety relay or from an emergency stop switch attached to the emergency stop input connector or safety I/O connector. After the signal is input, an SS1 is executed, and after the motor stops, the robot is in an emergency stop status. During the emergency stop status, EP is displayed on the 7-segment LED of the Robot Controller.
  There are three emergency stop circuits for the Robot Controller:

  • Emergency stop input connector (E-Stop)
  • Port of the safety I/O connector configured for the emergency stop (Safety Input)
  • Emergency stop switch attached to Teach Pendant (E-Stop, TP)

• Safeguard (SG) (protective stop)
  This function allows the robot to perform a protective stop by a signal input from a safety peripheral device attached to the safety I/O connector. After the signal is input, the SS1 is executed, and after the motor stops, the robot is in a protective stop status. SO is displayed on the 7-segment LED of the Robot Controller.
  The Robot Controller safeguard (SG) circuit is as follows.

  • Port of the safety I/O connector configured for the safeguard (SG)

• Enable
  Enable is the path connected to the enable switch when the Teach Pendant is connected. Only Epson Teach Pendants can be connected, and customer enable switches cannot be connected.
  When the system detects that the enable switch of the Teach Pendant is not in the middle position, the SS1 is executed, and the robot is in an STO state.

• Soft Axis Limiting
  This monitors that each axis of the robot is within its operating range. If the system detects that an axis of the robot exceeded the limiting range, the robot emergency stop and STO are immediately executed, putting the Robot Controller in the emergency stop status.
  The restricted range for each axis of the robot is set in the dedicated software (Safety Function Manager).

• Safety outputs
  External safety devices can be connected to the safety outputs of the Robot Controller to perform notifications of the ON/OFF status of the safety functions.
  By assigning settings in the dedicated software (Safety Function Manager), the following safety signals can be output:
  • STO state
  • Status of the emergency stop switch
  • Status of the enable switch
  • Enabled/disabled status of the Safety Limited Speed (SLS)
  • Enabled/disabled status of the Safety Limited Position (SLP)

Controller Safety Function charged optional functions:

• Safety Limited Speed (SLS)
  This monitors the operating speed of the robot. If the system detects that the robot exceeded the Maximum Speed, the robot emergency stop and STO are immediately executed, putting the Robot Controller in the emergency stop status.
  The safety speed limit of the robot is set in the dedicated software (Safety Function Manager).

  KEY POINTS

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  The speed monitoring function during teaching can be used as a standard function.

• Safety Limited Position (SLP)
  This monitors the robot's position and joint angles. If the system detects that the robot exceeded the monitored areas or joint angle limit, the robot emergency stop and STO are immediately executed, putting the Robot Controller in the emergency stop status.
  The Monitored Areas and Joint Angle Limit of the robot are set in the dedicated software (Safety Function Manager).