Integrated functional safety (FS)

Application

The safety design of integrated functional safety (FS) for machines with HEIDENHAIN controls offers supplementary software safety functions in addition to the mechanical safety features of the machine. For example, the integrated safety design automatically reduces the feed rate when you perform operations with open guard doors. The machine manufacturer can modify or expand the FS safety design.

Requirements

  • On controls with SIK:
    • Software option 160 (Integrated FS: Basic) or software option 161 (Integrated FS: Full)
    • Software options 162 to 166 (Add. FS Ctrl. Loop) or software option 169 (Add. FS Full) as needed
    • Whether you need these software options depends on the machine's number of motors.

  • On controls with SIK2:
    • Integrated FS: Basic software option (#6-30-1)
    • Integrated FS: Full software option as needed (#6-30-2*)
    • If your control is equipped with SIK2, software option #6-30-1 will enable four safe axes. You can order software option #6-30-2* multiple times and thus enable up to six additional safe axes.

  • The machine manufacturer must adapt the FS safety design to the machine.

Description of function

Every machine tool user is exposed to certain risks. While protective devices can prevent access to dangerous locations, the user must also be able to work on the machine without this protection (e.g., guard door opened).

Safety functions

To ensure that the requirements for operator protection are met, integrated functional safety (FS) provides standardized safety functions. The machine manufacturer uses the standardized safety functions for implementing functional safety (FS) for the machine in question.

You can track the active safety functions in the axis status of functional safety (FS).

The Axis status menu item

Description

Meaning

Short description

SS0, SS1, SS1D, SS1F, SS2

Safe Stop

Safe stopping of motors using different methods

STO

Safe Torque Off

The power supply to the motor is interrupted. Provides protection against unexpected start of the motors

SOS

Safe Operating Stop

Safe operating stop. Provides protection against unexpected start of the motors

SLS

Safely Limited Speed

Safely limited speed. Prevents the motors from exceeding the specified speed limits when the guard door is opened

SLP

Safely Limited Position

Safely limited position. Monitors safe axes to keep them within the limit values of a defined area

SBC

Safe Brake Control

Dual-channel control of the motor holding brakes

Safety-related operating modes of functional safety (FS)

Functional safety (FS) of a control offers various safety-related operating modes. The safety-related operating mode with the lowest number has the highest safety level.

Depending on how the machine manufacturer implements them, the following safety-related operating modes are available:

 
Machine

Refer to your machine manual.

The machine manufacturer must adapt the safety-related operating modes to each machine.

Icon

Safety-related operating mode

Short description

Operating mode SOM_1

Safe operating mode 1:

Automatic mode, production mode

Operating mode SOM_2

Safe operating mode 2:

Setup mode

Operating mode SOM_3

Safe operating mode 3:

Manual intervention; only for qualified users

Operating mode SOM_4

This function must be enabled and adapted by the machine manufacturer.

Safe operating mode 4:

Advanced manual intervention, process monitoring, only for qualified users

Functional safety (FS) in the Positions workspace

On a control with functional safety (FS), the monitored operating states of the speed S and feed rate F are displayed in the Positions workspace. If a safety function is triggered while in a monitored state, the control stops the feed movement and the spindle or reduces the speed (e.g., if a guard door is opened).

Axis display and position display

The Functional safety application

 
Machine

Refer to your machine manual.

The machine manufacturer configures the safety functions in this application.

In the Functional safety application in the Home operating mode, the control provides information about the status of the individual safety functions. In this application you can see whether individual safety functions are active and have been accepted by the control.

The Overview workspace in the Functional safety application

The Axis status menu item

The Axis status menu item in the Settings application

In the Axis status menu item of the Settings application, the control provides the following information about the status of the individual axes:

Field

Meaning

Axis

Configured axes of the machine

State

Active safety function

Stop

SLS2

Maximum speed or feed-rate values for SLS in the SOM_2 operating mode

SLS3

Maximum speed or feed-rate values for SLS in the SOM_3 operating mode

SLS4

Maximum speed or feed-rate values for SLS in the SOM_4 operating mode

This function must be enabled and adapted by the machine manufacturer.

Vmax_act

Currently valid speed or feed-rate limit
These are either values from the SLS settings or from the SPLC

If values are greater than 999 999, the control displays MAX.

The control shows the following icons and buttons:

Icon or button

Meaning

Reset the test status of the selected axis

Reset test flags

Reset the test statuses of all axes

 
Tip
  • Resetting of the test status is a function for the Service department. Use this function only if instructed by HEIDENHAIN or the machine manufacturer.
  • To reset the test status of axes, you need the NC.ApproveFsAxis right. This right is only available if user administration is active.
  • User administration

  • User administration roles and rights

Test status of the axes

In order for the control to ensure safe operation of the axes, it checks all monitored axes when the machine is switched on.

The control checks whether the position of an axis matches the position directly after shutdown. If a deviation is detected, the control marks the respective axis in the position display with a red warning triangle.

If checking of individual axes fails when starting the machine, you can check the axes manually.

Checking axis positions manually

The control indicates the test status of the individual axes with the following icons:

Icon

Meaning

The axis has been tested or does not need to be tested.

The axis has not been tested, but must be tested to ensure safe operation.

Checking axis positions manually

The axis is not monitored by functional safety (FS) or is not configured as a safe axis.

The axis is monitored by functional safety (FS), but the SLP safety function is deactivated.

In machine parameter safeAbsPosition (no. 403130), the machine manufacturer defines whether the SLP safety function is activated for an axis.

Checking axis positions manually

 
Machine

Refer to your machine manual.

This function must be adapted by your machine manufacturer.

The machine manufacturer defines the test position.

To check the position of an axis:

    1. Select the Manual operating mode

    1. Select Move to ref. point
    2. Select Check axis positions in the Referencing workspace

    1. Select the desired axis

    1. Press the NC start key

    1. The axis moves to the test position.
    2. After the test position has been reached, the control issues a message.

    1. Press the permissive button on the machine operating panel
    2. The control displays the axis as a tested axis.
     
    Notice
    Danger of collision!
    The control does not automatically check whether collisions can occur between the tool and the workpiece. Incorrect pre-positioning or insufficient spacing between components can lead to a risk of collision while approaching the test positions.
    1. If necessary, move to a safe position before approaching the test positions
    2. Watch out for possible collisions
     
    Tip

    In the Referencing workspace, you can switch as desired between the Referencing and Check axis positions modes.

    Notes

    • Machine tools with HEIDENHAIN controls may be equipped with integrated functional safety (FS) or with external safety. This chapter refers exclusively to machines with integrated functional safety (FS).
    • The control performs repeated self-tests to detect defective cables, for example. The machine manufacturer defines at what intervals the control will perform the self-tests. When a self-test of the control is active, the control displays an icon in the information bar. The control cannot perform any axis movements while a self-test is active.