Safety Functions

Types of Safety Functions

This Controller has third-party certification. The certified safety functions are combined and defined as the following safety functions of Epson.
The safety functions in this manual are described under Controller Safety Function Name.

Controller Safety Function Name Safety Function Certified by IEC 61800-5-2
STO STO
Emergency Stop E-Stop,TP Emergency Stop
Safety Input

Safety Input

SS1-r & SS1-t

Safeguard (SG)/Safeguard (Protective stop)

Safety Input

SS1-r & SS1-t

Enable Enable Switch Stop
Soft Axis Limiting SLP
Safety Outputs STO Safety Output
Emergency Stop
Enable
SLS (SLS_T, SLS_T2, SLS1-3)
SLP (SLP_A-C)
SLS (SLS_T, SLS_T2, SLS1-3) SLS
SLP (SLP_A-C) SLP

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.
Some safety features are paid options.

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 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 error 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 error status.
    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, putting the Robot Controller in the error status.
    The Monitored Areas and Joint Angle Limit of the robot are set in the dedicated software (Safety Function Manager).

Safety Parameters

The equipment manufacturer should select peripherals that can meet Cat. 3 PLd using the following values.

Common parameters

Safety Status Type of Element Proof Test Interval DC PL and Category SIL and HFT
STO B 20 years Medium PLd, Cat.3 SIL2, HFT1

Parameters for each safety function

Controller Safety Function Name Enable Mode Stop Category SFF

PFHd

10-7

Response Time (ms)
Emergency Stop E-Stop, TP ALL 1 98.7% 2.1 690
Safety Input ALL 1 98.8% 2.1 690
Safeguard (SG)/Safeguard (Protective Stop) AUTO 1 98.8% 2.1 700
Enable

TEACH

TEST

1 98.7% 2.1 690
Soft Axis Limiting

AUTO

TEST

1 98.7% 2.1 80
Safety Outputs STO ALL - 99.5% 1.5 680
Emergency Stop E-Stop, TP ALL - 99.4% 1.1 20
Safety Input ALL - 99.5% 1.1 20
Enable ALL - 99.4% 1.1 20
SLS ALL - 99.5% 1.1 50
SLP ALL - 99.5% 1.1 50
SLS ALL 1 98.7% 2.1 80
SLP

AUTO

TEST

1 98.7% 2.1 80

The B10D values for switches provided by Epson are as follows:

  • Emergency Stop switch (Option and TP): 250,000
  • Enable switch: 1,000,000