Speed Measuring With Two Sensors - Leibinger JET3 Series Operating Manual

Group 8

8.5.3.6 Speed measuring with two sensors

As an alternative to the use of an external encoder or a constant internal speed there is
a third option available:
The current production speed can be measured on the basis of the signals from two
sensors connected to interface X5. Sensor 1 has to be connected to X5.5 (PrintGo Gate
input) and sensor 2 to X5.4 (PrintGo input). With this setup PNP-sensors are required
for both inputs.
Function See Figure 158
Sensor setup:
The two sensors have to be mounted on the production line in a way that they can be
activated by the products passing by. For this the two sensors have to be mounted on the
same height (1) and at a distance from each other (2). As higher the production (line)
speed as larger should be the sensor distance. The maximum distance allowed is 250
mm (3). The distance between the two sensors has to be smaller than the distance
between two products (4). As a rule of thumb there must be never more than one product
between the 2 sensors! (5)
The actual distance has to be measured and entered in the corresponding input field (6).
With a product passing the first sensor (sensor 1) the speed measurement starts (7).
The measurment is stopped as soon as the product passes the second sensor (8)
(sensor 2). This second sensor (8) works also as the <PrintGo> sensor and controls the
start of the printout. It is mandatory that sensor 1 (start sensor for speed measuring)
is always mounted before sensor 2 (stop sensor for speed measuring and PrintGo
sensor).
The production speed is calculated from the time measured and the distance entered.
Working with short distances it may happen that right after the start of the production
line there are no values of the measured speed available. For this case the iternal
speed set (9) is taken as default.
JET3 Series
Job Editor Page 283
Release 2.02