Reset input

Edge-triggered input used for the following purposes:

  • Resetting error messages when the cause of the error is no longer present.

  • Manually removing a start-up inhibit which may have been specified with S_StartReset.

Data type: BOOL

Initial value: FALSE

The Reset input supports manual resetting of an active start-up or restart inhibit by the operator (see EN ISO 13849-1).

NOTE:

Resetting does not occur with a negative (falling) edge, as specified by standard EN ISO 13849-1, but with a positive (rising) edge.

Additional measures, e.g., an additional function stop, can be taken to reduce the risk of an unintended start-up.

Connection: With the signal of a reset button connected to the Safety Logic Controller (value TRUE or FALSE). Constant TRUE or FALSE values are not permitted.

Value

Description

FALSE

Error resetting and removal of an active start-up inhibit are not requested.

Edge FALSE > TRUE

Error resetting and removal of an active start-up inhibit are requested.

The function block performs internal edge monitoring for the Reset input. A reset is only executed on a positive signal edge. A further static TRUE signal after a positive signal edge has no effect.

Resetting the function block by means of a positive signal edge at the Reset input can cause the S_EDM_Out output to switch to SAFETRUE immediately (depending on the status of the other inputs).

 WARNING

UNINTENDED START-UP

  • Include in your risk analysis the impact of the reset by means of a positive signal edge at the Reset input.

  • Make certain that appropriate procedures and measures (according to applicable sector standards) have been established to help avoid hazardous situations when resetting.

  • Do not enter the zone of operation when resetting.

  • Ensure that no other persons can access the zone of operation when resetting.

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

Failure to follow these instructions can result in death, serious injury, or equipment damage.

NOTE:

If the function block is expecting a positive edge for resetting (inhibit is active or an error state applies), a static TRUE signal at Reset will be regarded as an error. In such cases, switch Reset to FALSE to exit the error state.