Reset input

Edge-triggered input used for the following purposes:

Resetting error messages when the cause of the error is no longer present.
Manually resetting a restart inhibit set using S_AutoReset (see EN ISO 13849-1).

Data type: BOOL
Initial value: FALSE

The Reset input supports manual resetting of a restart inhibit by the operator (see EN ISO 13849-1).

Hinweis
Resetting does not occur with a negative (falling) edge, as specified by standard EN ISO 13849-1, but with a positive (rising) edge.
To implement the reset with a falling edge (with regard to the mandatory acceptance procedure), use the safety-related function block SF_Reset.

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

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

WARNUNG

Unintended machine operation

Make certain that the Reset input is not connected to any other device than a suitable manual reset device.

Value Description

FALSE Error resetting and removal of an active restart inhibit are not requested.

Edge FALSE > TRUE Error resetting and removal of an active restart 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.
Refer to the first warning below this table.

Value	Description
FALSE	Error resetting and removal of an active restart inhibit are not requested.
Edge FALSE > TRUE	Error resetting and removal of an active restart 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. Refer to the first warning below this table.

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

WARNUNG

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.

If you have not activated a restart inhibit (S_AutoReset = SAFETRUE), a manual reset does not have to be performed following error removal. In such cases, the error message is confirmed automatically once the error is removed.

WARNUNG

Unintended start-up

Include in your risk analysis the impact of removing the cause of an error with regard to the automatic reset and restart of the machine if the restart inhibit is deactivated (S_AutoReset = SAFETRUE).

Make certain that appropriate procedures and measures (according to applicable sector standards) have been established to help avoid hazardous situations when removing the source of an error if the restart inhibit is deactivated.

Do not enter the zone of operation when removing an error under this condition.

Ensure that no other persons can access the zone of operation when removing an error under this condition.

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

Hinweis
If the function block is expecting a positive edge for resetting (restart 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.