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• TestTime input

TestTime input

Specification of the permissible response time for the signal changes of the individual sensor test phases.

Data type: TIME
Initial value: #10ms
Permissible maximum value: #150ms

Sensor test phases are described using the following signal sequence diagram.

Note The diagram only shows the inputs and outputs relevant for the description, and only a successful test is displayed.

Sensor test phase 1: A rising edge at the StartTest input causes the S_TestOut output to switch to SAFEFALSE and the monitoring time set at TestTime (phase 1) to begin. The sensor must switch the S_OSSD_In input to SAFEFALSE within the period specified at TestTime.

Sensor test phase 2: Once there is a SAFEFALSE at the S_OSSD_In input, the S_TestOut output is switched to SAFETRUE and a second monitoring time measurement (phase 2) begins with the time set at TestTime. The sensor must switch the S_OSSD_In to SAFETRUE within this period.

If one of the two time monitoring periods is exceeded, the function block switches the S_OSSD_Out output to SAFEFALSE and outputs an error (Error = TRUE) at the Error output.

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

Note An automatic test cycle extends the total response time for the safety-related function. This means the value for TestTime depends on the safety-related application involved and must be established as part of a risk analysis. Do not enter any other value than this.

WARNING

Non-conformance to safety function requirements Verify that the time value set at TestTime corresponds to your risk analysis. Be sure that your risk analysis includes an evaluation for incorrectly setting the time value for the TestTime parameter. Validate the overall safety-related function with regard to the set TestTime value and thoroughly test the application.