动物射频识别.第7部分:ISO 11785标准识别系统的同步

[中文适用范围]： 本部分的ISO 24631指定了用于同步RFID接收器在读取符合ISO 11784和ISO 11785的个体动物识别应答器时的规则和程序。此处所述的同步方案可以在每个阅读器中完全实现，当连接到同步总线时，这些阅读器将形成一个对等网络（所有阅读器平等 - 没有专用主设备）。此外，还可以通过专门的制造商特定同步接口将一组读者添加到总线中，可能采用主/从配置。同步接口在同步总线上呈现与单个对等读者相同的电气特性。根据ISO 24631-2规定的接收器符合性标准，允许激活时间窗口的公差为-0/+L ms，因此制造商可以自由选择其首选方法来检测HDX头部分或完整。无论如何，在同步阅读器时，无论使用哪种头部检测方法，所有阅读器都必须严格遵守给定时序和时间公差，如时间图所示。此外，还应特别注意故障诊断，这在读者网络由不同制造商的产品组成时变得更加重要。最明显的情况是，当一个作为网络一部分的读者断开（例如同步电缆断裂），它会认为自己现在处于独立状态，并被允许异步操作，从而损害其他所有阅读器。 [外文原描述]： ISO 24631-7:2012 specifies rules and procedures for synchronizing RFID transceivers while reading transponders used in individual animal identification complying to ISO 11784 and ISO 11785. The synchronization scheme described herein may be fully implemented within each reader, and such readers when attached to the synchronization bus create a peer-to-peer network (all readers are equal ? there is no dedicated master). Additionally, a cluster of readers, which could be in a master/slave configuration, may also be added to the bus using a dedicated, manufacturer specific Synchronization Interface. The Synchronization Interface presents to the synchronization bus electrical characteristics identical to those of a single peer-to-peer reader. The transceiver conformance standard ISO 24631-2 permits activation on/off timing tolerances of −0/+1 ms and therefore gives reader manufacturers options as to their preferred method for detecting the HDX header; partial or full. However, when synchronizing readers, irrespective of which header detection method is used, it is critical that all readers adhere strictly to the specific timings and timing tolerances as given in the timing diagrams. Particular attention should also be given to fault diagnostics which becomes more important when a reader network comprises products from different manufacturers. The obvious case is where a reader which is part of a network has become detached e.g. sync cable break, and it considers it's self to be now standalone and thus permitted to operate asynchronously to the detriment of all other readers.