SICK WTT12-S Instrucciones De Funcionamiento página 21

4.6.2 Requirements on the higher-level controller
8029123/2024/01/15 | SICK
Subject to change without notice
Function 2: Absence of reference object or reference area
B
Figure 12: Alignment
Sensor
1
Light beam
2
A Distance front of sensor to reference surface
B Distance reference surface to step
Table 5: Detection corridor
A Distance front of sensor to reference surface
B Distance reference surface to step
To integrate the device into systems with more stringent requirements on functional
safety, it is necessary to use diagnostic options,
age", page 19.
• The higher-level controller or test device must be implemented in accordance with
the functional safety standards relevant to the area of application and, in this
regard, must fulfill a safety level sufficient for the application. The requirements on
SIL1 according to IEC 61508 and PL c (Cat 2) according to ISO 13849-1 must be
fulfilled as a minimum.
• The higher-level controller must provide fault detection and a test device that
regularly switches the test input according to the requirements of the application.
The test rate must be at least 100 times the expected average demand rate. If
the test fails, the higher-level controller must detect an error and maintain or bring
about the safe state of the application.
• The higher-level controller must recognize the frequency-modulated signal
"Data sheet", page 30) as a valid input signal.
• The higher-level controller must monitor the frequency of the signal. If the fre‐
quency deviation is more than 2%, the higher-level controller must detect an error
and maintain or bring about the safe state of the application.
•
If the level at the Q output of the sensor is permanently LOW, the higher-level
controller must maintain or bring about the safe state of the application.
• If the level at the Q output of the sensor is permanently HIGH, the higher-level
controller must detect an error and maintain or bring about the safe state of the
application.
• The higher-level controller must monitor the supply voltage of the sensor. If the
supply voltage exceeds the specified range, the higher-level controller must detect
an error and maintain or bring about the safe state of the application.
OPERATING INSTRUCTIONS
1
2
α
150 ... 2,000 mm
> 85 mm (min. step height: B * sin α
see "Measures for diagnostic cover‐
O P E R A T I N G I N S T R U C T I O N S | WTT12-S
en
(see
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