Interface A2, Release Date: 02.03.2022
Page 25
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
“Channel by Inputs:
Detection”:
The output is assigned to the channel selected by the digital optocoupler
inputs in mode “detection”: The signal is set when an object is detected by
the assigned channel.
“Channel by Inputs:
Quantity”:
The output is assigned to the channel selected by the digital optocoupler
inputs in mode “quantity”: The signal is set when the by parameter “quanti-
ty” defined number of objects is detected by the assigned channel.
For all inputs and outputs or I/Os, the polarity can be selected arbitrarily. For an output that is assigned to a
channel, you can also specify whether a signal should only be generated once, how long a signal should be
present at the output, and whether it should be output with a delay. If a counting function is assigned to the
output (mode “quantity“), the quantity up to which to be counted to before the signal is output can be speci-
fied.
4.16
Timer
The LVMC provides two timers: A so-called "Object Detection Timer" and a "General Purpose Timer". If acti-
vated, the "Object Detection Timer" will start when an object enters the sensing area. It is stopped by a posi-
tive or negative edge of the signal of an optocoupler input. The general purpose timer is started and stopped
by a positive or negative edge of the signal from an optocoupler input, either by the same input or by a differ-
ent input.
For example, by connecting two light curtains and using the object detection timer, it is possible to determine
the speed of an object passing the sensing areas of the two light curtains.
4.17
Speed Measurement
An LVMC with connected CMT can be used for speed measurement. It is based on the two timers. The speed
that can be displayed via the CMT is determined according to the formula v=s/t (speed = distance per time)
using a measurement distance that can be specified for each activated timer.
A possible arrangement consists of two interconnected LVMCs. An object first falls or flies through the sens-
ing area of the first light curtain and subsequently through the sensing area of the second. The second LVMC
is configured so that the signal of an optocoupler output is set, when the object enters the sensing area. This
optocoupler is connected via a wire to an optocoupler input of the first LVMC. This input is assigned to the
“Stop Object Detection Timer” function in the first LVMC, the object detection method is set to “Each channel
separately, when object is entering the sensing area". As soon as the object enters the sensing area of the
first light curtain, the object detection timer of the second is started. When it enters the sensing area of the
second light curtain, the timer is stopped again. Thus, the object detection timer measures the time the ob-
ject takes to bridge the distance between the sensing areas of the two light curtains. Based on the entered
distance between the two LVMCs, the speed can be determined.
4.18
Date and Time
The clock implemented in the LVMC does not continue to run when power is turned off. Available is the time
that has elapsed since the LVMC was switched on or restarted, as well as the time that has elapsed since the
LVMC switched to the “running” state. If the light curtain is connected to an Ethernet network, the firmware
attempts to reach an NTP server and obtain the current date and time from it.