Scanner Starts Scanning AFTER Pallet Passes the Sensor – Banner Engineering QS18E Photo Eye Sensor Problem Article
Target Audience: Advanced User, Maintenance Technician
Article #: 13902
Summary
This Problem Article explains why a Banner QS18E Photoelectric sensor may trigger a scanner AFTER a pallet passes the sensor instead of DURING the passing of the pallet. The sensor can be set to trigger AS the pallet passes or set to trigger AFTER the pallet passes the sensor.
Situation and symptoms
- Pallet approaches sensor
- Pallet crosses in front of sensor but sensor does not trigger the scanner
- Pallet leaves the sensor and THEN the sensor triggers the scanner
Explanation
In an application where the photo eye should trigger a scanner when the pallet or product passes in front of it, the QS18E should be set to DARK mode. That means it triggers the scanner when the reflection from the sensor reflector (on the other side of the conveyor) is blocked and goes from ‘light’ to ‘dark’.
If the QS18E is in LIGHT mode, the opposite will occur. The photo eye triggers the scanner when the reflector goes from ‘dark’ to ‘light’. Thus, the pallet LEAVING the photo eye triggers it to start the scanners AFTER the pallet leaves.
Solution
Put the sensor into DARK mode.
This is done by pressing the button on the back of the QS13E in the correct sequence. The manual below provides the sequence. The key area of the manual is here:
Additional comments and full product manual
Issue Found: Banner QS18EP6XLPCQ8 Photoelectric Sensor