Siemens SIMATIC ET 200S - Differential travel parameter

4 IQ-SENSE
13-6
ET 200S Distributed I/O System
EWA-4NEB 780602402-12
Reflection light probe
Transmitter
Object
Switching status 0: No object detected, i.e.
the object is not in the light beam. The
receiver does not detect any light.
Switching status 1: Object detected, i.e. the
object is in the light beam. The receiver
detects light.
Receiving
stations
Transmitter
Receiving
stations
Reflection light probe
Figure 13-2 Reflection light probe
Reflection light barrier
Object
Switching status 0: No object detected, i.e.
the object is not in the light beam. The
receiver detects light.
Switching status 1: Object detected, i.e. the
object is in the light beam. The receiver
does not detect any light.
Transmitter
Receiving
stations
Transmitter
Receiving
stations
Reflection light barrier
Figure 13-3 Reflection light barrier
13.1.4 Differential travel parameter
Features
”Signal flutter” may occur as a result of interference at the reflection light probe or
during the production process. The measured value will swing around the switching
threshold of 100% (object detected -- object not detected). This flutter at the
switching threshold can be prevented with the differential travel parameter . This
will ensure a stable output signal at the sensor.
The ranges 5/ 10/ 20/ 50% can be configured as differential travel.
Prerequisites
The differential travel parameter can only be configured for reflection light probes
with background shielding.