For materials that are fast-flowing or have longer delivery times, replenishments must be requested early. To prepare for the necessary requirements, one roller conveyor can be equipped with several sensors, which together continuously transmit the precise number of available small load carriers (SLC) to the control system. This occupancy monitoring allows the system to accurately and precisely identify future requirements to avoid bottlenecks and standstills.
Multiple intelligent signaling devices on a single roller conveyor with a first in, first out (FIFO) rack facilitate precise monitoring of the SLC available. Each sensor transmits any changes in status via the wireless network to the material flow control system in real time, which allows the system to determine actual occupancy. The intervals between status changes enables the system to make predictions regarding future requirements. If the system can tell that an additional SLC will have been removed by the time an automated guided vehicle (AGV) has arrived at the rack, it can ensure that the AGV is automatically loaded with an additional carrier even before the AGV has set off. The number of sensors necessary depends on the speed of flow of the material in question and its delivery time.
In addition to automatic replenishment of materials, the use of two or more sensors on one roller conveyor can also facilitate intuitive signaling of stock status in the form of a traffic light system—either directly from a specific rack or in the management system. Depending on the occupancy status detected by the sensors, the traffic light would be green if all places are occupied, orange if only some are occupied, and red if all are empty.