The feed presence sensor (FPS) monitors the operation of the feeding system. After a feed motor on top of the feed tube is activated, the FPS monitors the vibrations in the sensor plate caused by the falling feed. Four feed pipes (with different types of feed) can be monitored separately.
Every feed type that contains hard particles (which create clear vibrations on the sensor plate) can be detected. The finest feed that can be detected is soya bean pulp. Minerals and liquids cannot be detected by the feed presence sensor. When a feed tube is blocked or the feed supply is empty, no feed is detected by the FPS, and it will generate an alarm. This alarm is not critical, and the robot will continue milking. The alarm will show up when 50 feed actions out of the last 100 are not detected by the FPS. 100 feed actions will be reached in 2-4 cow visits.
The feed presence sensor plate must be cleaned regularly with a brush to remove feed which is clogged on the sensor. For optimal performance it is recommended to clean the feed presence sensor every week. Do NOT clean with a hose as this will cause the feed particles to stick to the wet surface and give bad results, and possibly get the electrical connections wet too.
Before use, the FPS must be calibrated for two reasons:
1. Different types of feed create different levels of vibrations on the sensor. The threshold value feed/no feed is based on the level of vibrations of the specific type of feed.
2. The FPS can detect feed (vibrations) on 4 positions. During the calibration, the FPS makes a link between a feed tube and a specific position on the FPS. After dispensing feed, the FPS now monitors the vibrations of the specific spot on which it expects the feed.
The calibration is separately done per feed type and feed tube and is finished when the average sensor value is <10% deviating from the previous value and a maximum of 10 feed portions are dosed during calibration. If more than 10 feed portions are required, the calibration is failed, and you can either choose to calibrate the FPS again or choose that the FPS will not operate for this feed type.
Reach out to one of our Technician or your FMS specialist to learn more.