| 摘要 |
The present invention provides a method and a device for increasing the coverage in a shop data system for each individual information module (B1 - B10), which has a low output power for its messsage acknowledgement at the reception of information, ensuring that a signal of acknowledgement indicating reception of information reaches a system computer. An information device, for instance a shelf-edge module (B5), which has received a correctly decoded information intended for this particular module, emits a signal of acknowledgement, which then is repeated by said other modules (B1 - B4, B6 - B10), which also have decoded said message finding that it was not intended for them. These modules (B1 - B4, B6 - B10) switch to a repeater mode so that said signal of acknowledgement emitted by said addressed module (B5), will be repeated by each such other module in said repeater mode, which perceives said signal of acknowledgement, said signal of acknowledgement propagating back to said transmitting unit (TX) during a period of time between transmitted messages. Herethrough, it is only required, that each information module has a coverage for its signal of acknowledgement such that this signal reaches at least one other additional information module. |
