Explanation of Robot Controller Safety Functions

The Robot Controller safety functions can be used to set safety inputs and safety outputs, and to create applications that link to safety devices.

Also, the safety function options support functions that safely control the operating speed and operating range of the robot. You can set the robot's Maximum Speed and monitoring area to achieve an application for safely controlling the robot.

CAUTION


The safety performance of the Robot Controller safety functions is Category 3, PLd (Reference standard: ISO 13849-1: 2015).
Please ensure the safety of the robot system in light of the safety performance of the Robot Controller safety functions. Also, please refer to and observe the safety standards of the respective country and region.

The following describes the types and characteristics of the Robot Controller safety functions.

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 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 follow:

    • 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 executed and the robot is stopped. For details on the status, display, and notification of the Robot Controller when stopped by the safety function, refer to the following.
    Precautions for Using the Robot Controller Safety Functions
    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 and the robot is stopped. For details on the status, display, and notification of the Robot Controller when stopped by the safety function, refer to the following.
    Precautions for Using the Robot Controller Safety Functions
    The safety speed limit of the robot is set in the dedicated software (Safety Function Manager).

    KEY POINTS


    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 and the robot is stopped. For details on the status, display, and notification of the Robot Controller when stopped by the safety function, refer to the following.
    Precautions for Using the Robot Controller Safety Functions
    The Monitored Areas and Joint Angle Limit of the robot are set in the dedicated software (Safety Function Manager).

Reference
For details on each function, refer to the following sections.

Standard functions:

Paid option functions:

KEY POINTS


For details on the "Safety Function Manager," refer to the following section.

Setting Safety Functions
(Setting Software: Safety Function Manager)