Detectability of discrete event systems, defined as the ability to determine the current and subsequent states, is very important in diagnosis, control, and many other applications. So far only detectability of non-networked discrete event systems has been defined and investigated. Non-networked discrete event systems assume that all the communications are reliable and instantaneous without any delays or losses. This assumption is often violated in networked systems. In this paper, we study detectability for networked discrete event systems. We investigate the impact of communication delays and losses on detectability. We define two classes of detectabilities: network detectability for determining the state of a networked discrete event systems and network D-detectability for distinguishing certain pairs of states of the systems. Necessary and sufficient conditions for network detectability and network D-detectability are derived. Methods to check network detectability and network D-detectability are also developed. Examples are given to illustrate the results.

中文翻译：

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网络离散事件系统的可检测性

离散事件系统的可检测性，定义为确定当前和后续状态的能力，在诊断、控制和许多其他应用中非常重要。到目前为止，只定义和研究了非网络离散事件系统的可检测性。非联网离散事件系统假定所有通信都是可靠和即时的，没有任何延迟或损失。这个假设在网络系统中经常被违反。在本文中，我们研究了网络离散事件系统的可检测性。我们调查了通信延迟和丢失对可检测性的影响。我们定义了两类可检测性：用于确定网络离散事件系统状态的网络可检测性和用于区分系统某些状态对的网络 D 可检测性。推导出网络可检测性和网络D-可检测性的充要条件。还开发了检查网络可检测性和网络 D 可检测性的方法。给出了例子来说明结果。