Individual Activation of Safety Equipment

Individual activation/deactivation of safety equipment refers to the possibility of manually connecting and disconnecting different, mutually independent safety-related functions. This equipment cannot be operated when disconnected.

WARNUNG

Unintended start-up

Be sure that your risk analysis includes an evaluation for the deactivation of safety equipment.

Make certain that appropriate procedures and measures (according to applicable sector standards) have been established when deactivating safety equipment.

Use appropriate safety interlocks where personnel and/or equipment hazards exist.

Single-channel application

The graphic below shows a code example for this type of individual deactivation in a single-channel layout.

In this example, different items of safety equipment, which are evaluated by different safety-related function blocks, act on different safety-related outputs of the Sicherheitssteuerung: For the function block SF_EmergencyStop on output S_EStopOut (global I/O variable EStop_Out) and for SF_GuardMonitoring on output S_GuardMonitoring (global I/O variable SGMon_Out). These outputs control different safety-related functions.

The safety-related function blocks are activated (with the Activate input) via different signals or Sicherheitssteuerung inputs.
When a safety-related function block is deactivated (with the Activate input), the relevant output/safety zone is disconnected.

Two-channel application

If the risk analysis shows that the safety equipment needs to be implemented on a two-channel basis, the example shown above must be implemented with two-channel input/output signals.