Bulk reading of RFID label-carrying objects is currently the method chosen by customers of convenience for inventory management. The process involves a group of objects, all of them RFID tagged, and all of them are read completely from one single reader position at one time. The speed of bulk reading is often increased with RFID encryption, or pure software approaches, in order to avoid data transmission problems due to exclusion range. Incorrect object labels are read either by the reader itself, or by a special reader. Both systems supply missing information in a timely manner to the reading process. However, as the tags respond strictly sequentially, the time needed to read them grows linearly with the number of labels. This means that it takes at least twice as long to read twice as many labels. Due to collision effects, the time required is greater. Therefore, for the purpose of inventory management, bulk reading is not appropriate. It is only a rough guide. It is just a way to know that an object is there or not, but the system user must be ready to change the system operation.
Bulk reading will not detect or indicate spoilage. It will not identify mislabelled objects. It is not feasible at all times to continuously observe object labels to detect problems with accurate labelling. Bulk reading is primarily suited to keep track of large groups of objects which are either re-labelled or are characterised by their limited processing demands. Near real-time detection of changing quality/status in object labels would provide feedback to the manufacturing assembly line, allowing for immediate intervention.
Scan data from passive tags is broadcast into a computer using a wireless reader and is read by software in the computer. The reader listens for responses broadcast by the tags in the near field. When a tag responds to the reader, the reader sends a radio frequency signal to the tag, if it can. Responses from the tag in the near field are read and stored in the computer system. If more than one tag responds, the computer decides which of the responses to disregard as the tag is not recognisable. d2c66b5586