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Datalogic - SR21 - Slot sensor

  • 2mm slot gap
  • High 25 kHz switching frequency
  • Detection of semi-transparent labels
  • IR or red/green light models
  • PNP or NPN output

Product description


The SR21 series is a photoelectric slot sensor with 2mm slot width, are characterised by a high 12 bit (4096 steps) resolution, a low 20µs response time and a switching frequency reaching

25 kHz.


The setting of the switching threshold is carried out automatically by simply pressing a push-button, or dynamically during label (or other reference) movement. The SR21-IR model with infrared emission is ideal for label or hole detection on continuous surfaces, while the SR21-RG model with double red or green emission suits colour print register mark detection on transparent films for automatic packaging.




• Teach-in setting: easy and fast setting procedure

• Dynamic setting: possibility to set the sensor while the label is moving

• 25KHz switching frequency

• Red/Green emission model: possibility to perform contrast application




• Packaging lines

• Labelling machines

• Paper and Printing machines


Part numbers

Parts Price Light type Weight
IR LED 115 g
Green LED, Red LED 120 g


953151070 Label Sensor Infra Red PNP/NPN

Technical data

Approvals CE, UL
Dimension (mm) 20 x 90 x 26
Electrical connection M8 4-pole connector
Fork depth 50 mm
Fork gap 2 mm
Frequency 25000 Hz
IP class IP65
LED indicator Yes
Lens material Glass
Light type IR LED
Material of body Zinc Alloy
Output NPN, PNP
Output current max 0,1 A
Photocell technology Fork
Power consumption max 0,55 A
Reaction time 0,02 ms
Supply voltage 10-30 V DC
Temperature operational max 60 °C
Temperature operational min -20 °C
Weight 115 g
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