1. Operating Manual
2. Operation
3. Special Guiding and Monitoring Functions
4. Watchdog

Function

The Watchdog function is used to prevent the web from wandering after the total loss of the guiding criterion (printed line, contrast transition or print feature) during line, contrast or feature guiding. If the guiding criterion disappears from the scanning area of the line, contrast or object sensor (e.g. if the print is not carried out, a poor splice or similar), the current web position is detected by the edge sensor (capture sensor) and saved by the controller. Then the controller will switch over from the line, contrast or object sensor (Sensor 3) to the edge sensor (Sensor 1 or Sensor 2) used. Switching back to the line, contrast or object sensor is carried out automatically immediately after re-detecting the guiding criterion. When the Watchdog function is activated, the scanning area of the capture sensor is limited to 80%.