SF_TestableSafetySensor (FB)

FUNCTION_BLOCK SF_TestableSafetySensor

This function block detects, for example, the loss of the sensing unit detection capability, the response time exceed-ing that specified, and static ON signal in single-channel sensor systems.
It can be used for external testable safety sensors (ESPE: Electro-sensitive protective equipment, such as a light beam).
InOut:

Scope

Name

Type

Initial

Comment

Input

Activate

BOOL

FALSE

Activation of the FB.

S_OSSD_In

BOOL

FALSE

Status of sensor output, e.g., light curtain. FALSE: Safety sensor in test state or demand for safety-related response. TRUE: Sensor in the state for normal operating conditions.

StartTest

BOOL

FALSE

Input to start sensor test. Sets “S_TestOut” and starts the internal time monitoring function in the FB. FALSE: No test requested. TRUE: Test requested.

TestTime

TIME

TIME#10ms

Test time of safety sensor. Range from 0 to 150ms.

NoExternalTest

BOOL

FALSE

Indicates if external manual sensor test is supported. FALSE: The external manual sensor test is supported. Only after a complete manual sensor switching sequence, a automatic test is possible again after a faulty automatic sensor test. TRUE: The external manual sensor test is not supported. An automatic test is possible again without a manual sensor switch-ing sequence after faulty automatic sensor test.

S_StartReset

BOOL

FALSE

Start behaviour of safety FB

S_AutoReset

BOOL

FALSE

Behaviour on error of safety FB

Reset

BOOL

FALSE

Manual reset of FB

Output

Ready

BOOL

FALSE

Activation of the FB. TRUE indicates that the FB is activated and the outputs results are valid, FALSE the FB is not active and the program is not executed.

S_OSSD_Out

BOOL

FALSE

Safety related output indicating the status of the ESPE. FALSE: The sensor has a safety-related action request or test error. TRUE: The sensor has no safety-related action request AND no test error.

S_TestOut

BOOL

FALSE

Coupled with the test input of the sensor. Although specified as SAFEBOOL, in practice this signal will often be connected to a BOOL output. FALSE: Test request issued. TRUE: No test request.

TestPossible

BOOL

FALSE

Feedback signal to the process. FALSE: An automatic sensor test is not possible. TRUE: An automatic sensor test is possible.

TestExecuted

BOOL

FALSE

A positive signal edge indicates the successful execution of the au-tomatic sensor test. FALSE: An automatic sensor test was not executed yet or an automatic sensor test is active or an automatic sensor test was faulty. TRUE: A sensor test was executed successfully.

SafetyDemand

BOOL

FALSE

Output indicating that the FB is active and the primary safety function is demanded (e.g. related to the safety functionality).

ResetRequest

BOOL

FALSE

Output which can be used to signal the operator to press the reset functionality to continue.

Error

BOOL

FALSE

Error flag

DiagCode

WORD

0

Diagnostic register