Fill level monitoring in large vibration feeders can be optimally implemented using a US-M18 series ultrasonic sensor in combination with SB-RGB signal lighting. M18 ultrasonic sensors are suitable for larger working distances and for detecting shiny and even transparent components. Using IO-Link, the exact switch point of the sensor can be defined. This setting is tamper-proof. If the fill level falls below the target value, the switching output of the sensor switches and the yellow light of the signal lighting indicates that material must be refilled.