NoExternalTest input

Edge-triggered input for the optional specification of a required manual sensor test in the event of an error during the automatic sensor test phases.

If an error occurs during the sensor test phases performed by the function block, this error can be removed by means of an additional manual test (as described below).

If the risk analysis you performed indicates that the error is to be removed by performing a manual test, switch NoExternalTest to FALSE or connect a FALSE constant.

Data type: BOOL
Initial value: FALSE

Background: Manual sensor test in the event of an error. After a sensor test has taken place with errors, the safety-related sensor must always be verified to ensure it is functioning properly.

To carry out a manual sensor test, you must perform the steps below in the order specified:

Activate the reset button (positive edge at the Reset input).
Interrupt the light beam of the safety-related equipment (S_OSSD_In switches from SAFETRUE to SAFEFALSE).
Stop the interruption of the light beam of the safety-related equipment (S_OSSD_In switches from SAFEFALSE to SAFETRUE).
Activate the reset button again (positive edge at the Reset input).

Note
Once this sequence of steps has been carried out, a new sensor test must be requested by means of a positive edge at the StartTest input.

Connection: Connect this input to a time literal, i.e., to a constant of the data type TIME.

WARNING

Non-conformance to safety function requirements

Verify that the value set at NoExternalTest corresponds to your risk analysis.

Be sure that your risk analysis includes an evaluation for incorrectly setting the time value for the NoExternalTest parameter.

Validate the overall safety-related function with regard to the set NoExternalTest value and thoroughly test the application.

Value Description

TRUE No additional manual sensor test is required in the event of an error occurring during the sensor test phases performed by the function block.

FALSE A manual sensor test is required in the event of an error occurring during the sensor test phases performed by the function block.

Value	Description
TRUE	No additional manual sensor test is required in the event of an error occurring during the sensor test phases performed by the function block.
FALSE	A manual sensor test is required in the event of an error occurring during the sensor test phases performed by the function block.