Interface A2, Release Date: 02.03.2022
Page 17
LVMC User Manul A2 - 499.027.82
OPTRONIC AG
SWITZERLAND
Unteregger Strasse 53
CH-9403 Goldach
Phone: +41 (0)71 844 02 00
Fax:
+41 (0)71 844 02 10
e-mail: [email protected]
web: www.optronic.ch
4.4
Counting Channels
The LVMC provides four counting channels for simultaneous detection of different objects. Each channel can
be parameterized individually and detects the objects matching the parameters. he following parameters can
be specified for each channel:
“Minimum Size“:
The minimum object size that is detected by the channel. The LVMC sub-
tracts a safety margin from this value, and in reality uses the lowered value as
lower limit, in order to guarantee, that no objects get missed.
“Minimum Passing Time”: The minimum time an object must cover the sensing area so that it is count-
ed by the channel.
“Minimum Area“:
The minimum area an object must have so that it is counted by the channel.
To calculate the area, the LVMC sums up the measured object size (the cov-
ered part of the sensing area) over the time the object passes the sensing
area. Therefore, the area must be entered in unit time multiplied by length.
This parameter can be used as a replacement for channel parameters “Mini-
mum Size” and “Minimum Passing Time”, as they also define a simplified
area.
“Gap Suppression Time “: An object may have one or more locations with size smaller than the mini-
mum size entered for the channel. By use of this parameter, this form of gaps
can be suppressed. Enter the maximum time a gap that should be sup-
pressed can last.
“Minimum Expected
Passing Time“:
The minimum time a part is assumed to cover the sensing area. If an object
is detected by the channel, the channel does not count another object until
this time has passed. If this time expires while the sensing area is already
covered by another object, this part is also not counted.
This parameter is available for compatibility with the previous device genera-
tion. It is replaced by parameter “Gap Suppression Time”.
For analysis purposes, several measured values are recorded per channel: The passing time for the last
counted object, as well as the shortest and longest passing time of all counted objects. The values are delet-
ed when the LVMC is restarted, or when the values are manually reset via the CMT.
4.5
Minimum Required Passing Time / Oversampling
The minimum required dwell time specifies the minimum amount of time that an object must cover the sens-
ing area to be detected. The time can be adjusted in 30us steps, the minimum value (referred to as “Time
Resolution” in the CMT) depends on the light curtain type. The standard version supports a minimum passing
time of 480us, special versions with up to 30us are available on request.
With the minimum required passing time, the oversampling rate of the LVMC is internally determined: A long-
er minimum required passing time gives the light curtain more time to acquire measurement data, internally
several scans are combined into one measurement value. This makes the light curtain less sensitive to inter-
ference such as electromagnetic fields, light flashes or vibrations.