© SICK AG • Presence Detection • Subject to change without notice • 8015887
17
Operating instructions Register sensors RS25
Structure and function
4.2
Function
The RS25 register sensor is an opto-electronic sensor intended for
non-contact recognition of print marks in the printing industry.
The RS25 register sensor consists of an evaluation unit and an optical sen-
sor head. The optical sensor head is firmly connected to the evaluation unit
via one fiber-optic cable each for the transmitter and receiver.
The printing industry uses print marks, such as triangles, for lateral and
longitudinal register monitoring. The edges are detected by the register
sensor RS25.
The register sensor RS25 is connected to Ethernet Powerlink. Ethernet
Powerlink supplies a high-resolution NetTime for synchronization via the
network. All detected edges are transmitted from the RS25 register sensor
to the PLC with the NetTime as a reference.
In this way, high-quality information is provided to the PLC. The PLC can cal-
culate the lateral and longitudinal offset using the exact timing of the rising
and falling edges. For longitudinal monitoring, the distances of the front
edges are calculated. For lateral monitoring, the thickness of the mark is
compared with the thickness of the previous marks.
R
G
B
Very light blue colored paper/foil backround
Blue
Pink
Black
Bright yellow
Bright blue Orange/Red
Individual thresholds
in memory
Mark
No.
Threshold
LED
Analog
Digital
output
Bad side register
Bad length register
Color
value
Fig. 5: Function of the RS25
