KEYENCE LS-7000 - Manual (Page 70)

4-18
Chapter 4 Function Settings
4
Change of Edge Detection Threshold
The following section provides information on how to make threshold changes for the
measurement of highly transparent objects.
Transparent
tape
Threshold
(50%)
50% threshold
Position Position
Optical
reception
Brighter
Darker
Optical reception
Brighter
Darker
Light blocked
by tape
Measuring range
Detection impossible
Threshold
(80%)
80% threshold
Detection
possible
When measuring a highly transparent
target, such as a plastic tape, the
amount of light blocked by the tape is
minimal. Therefore, the tape may not be
detected if the threshold is low. In that case, increase the threshold level
so that the tape will be detected
Setting Range
The threshold can be set between 10% and 99% in 1% increments.
Note: • Only a single threshold can be set for each measuring head.
• In the measurement using the window edge such as T-EDGE or B-EDGE,
the measurement may become unstable with a higher threshold. In such a
case, use the reference edge or edge 0.
■ Optical Reception Waveform Output
While making a threshold setting for the target in the measuring area, an oscilloscope
can be used to output the optical reception waveform of the target so that the threshold
can be adjusted while monitoring the waveform.
Threshold level
(OUT2 analog output on terminal 23)
Optical reception waveform
(OUT1 analog output on terminal 22)
Approx. 450 ms
Approx.
10 ms
10V
Approx. 6.5 V
0V
Trigger pulse