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Trigger
In this measurement mode a single measurement is taken against an external pulse
signal. This signal can come from the controller or can be generated through another sensor, for
example a light barrier.
Trigger
Sensor LMA/B has an additional input to trigger a single measurement when an external event occurs.
Trigger input reacts only if
Trigger
as a measurement mode has been selected. Trigger input voltage
must be 24 V DC.
External trigger signal must be a digital one with clearly defined edges. A distinction is made between
rising edge (from low to high) and falling edge (from high to low):
According to the selection, measurement will be activated through a rising edge or falling edge of the
trigger. The selection of both is also possible; in this case measurement will be activated through any
edge. If it has been activated, trigger will not react to any new edge (trigger pulse) until measurement
cycle has been completed. Trigger pulses during measurement will be ignored.
Box
trigger-delay in ms
can be used to set a millisecond delay between trigger pulse and
measurement start. Time can be set between 1 ms and 60 000 ms.
(0= trigger delay inactive).
Error display duration
When an error in calculating the distance value occurs, the device will be able to provide a message.
This setting defines how long the internal error will appear through the LED or on output Q3.
Values between 1 ms and 60 000 ms can be set. (0 = error message display inactive)
Keep last measured value in case of error
This setting determines the analog output behaviour in case of error. If you tick the box
Keep last
measured value in case of error
, the last distance value before error will be available on the analog
output until correct distance measurement has been restored. If the box is unchecked, distance 0 will
be produced on the analog output.
Q3 is Alarm Output and active if:
You can here assign an alarm behavior to switching output Q3 and define when.
Different types of error can be selected, for which an output signal will be sent.
Error
Bescription
Measurement period too short
Measurement time is not enough to produce a distance
value
Measuring signal too weak (reflection
too low)
Object reflectivity is not enough
Measuring signal too strong (reflection
too high)
Object reflectivity is too high
Measuring signal faulty
Measurement signal is disturbed, for example due to
environment conditions or interference from other light
sources
Distance outside the measuring range
Distance value has been calculated but is outside the
selected measurement range
Device temperature exceeded
The internal sensor temperature lies above the admitted
operating temperature.
Device temperature underrun
The internal sensor temperature lies under the admitted
operating temperature.
Hardware error (device failed)
Unplug briefly the equipment from the mains and restart
operation. Should the error show again, ask the
manufacturer.
