Siemens SIMATIC ET 200S Manual page 503

14.1.4 Switching hysteresis parameter
Features
Faults with the diffuse sensor or in the production process can result in signal
wobbles. The measured value then changes the switching threshold by 100 %
(object detected – object not detected). You can prevent this switching threshold
wobble using the switching hysteresis parameter. This will ensure a stable output
signal on the sensor.
You can parameterize 5%/10%/20%/50% for switching hysteresis.
Requirements
You can only set the switching hysteresis parameter for diffuse sensors with
background fadeout.
Operating principle
100%
1
0
Figure 14-4
ET 200S Distributed I/O System
EWA-4NEB780602402-09
Receiving level
Switching
threshold
Switching hysteresis parameter
4 IQ-SENSE
Switching hysteresis
5%/10/20%/50%
Time
Switching output on the
sensor
Time
t
t
14-7