For materials which are fast-flowing or have longer delivery times, it is imperative that replenishments are requested early. For advance planning of 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 permanent monitoring of occupancy facilitates precise identification of future requirements, whereby bottlenecks and standstills can be predicted and thus avoided.
Multiple intelligent signalling devices on a single roller conveyor within an 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. The system then ascertains actual occupancy from this information. The intervals between status changes enable the system to make predictions regarding future requirements. If it is already foreseeable when an automated guided vehicle (AGV) is about to set off, for example, that by the time it has arrived at the rack in question an additional SLC will have been removed, then the AGV can automatically be loaded with an additional carrier. The number of sensors necessary here 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 signalling of stock status in the form of a traffic light system – either directly from the rack in question, or in the management system. Depending on the occupancy status detected by the sensors, the traffic light would then be green if all places are occupied, orange if only some are occupied, and red if all are empty.