Industrial wireless sensor networks (IWSNs) have mainly been used to monitor applications, but recently an interest in control and safety applications has emerged. Functional safety and communication in open transmission systems have been laid down in the IEC 61784-3-3 standard. The standard is based on a cyclic polling mechanism, which consumes a considerable amount of bandwidth; since existing IWSNs are very resource-constrained, this becomes a major challenge. To overcome this problem, this paper proposes a novel framework that uses an event-triggered failsafe mechanism based on synchronous wired polling and wireless time-slotted time division multiple access. We analytically derive the minimum and maximum bound for the most important metric for safety-critical applications, safety function response time (SFRT). A new metric, normal state interrupt time (NSIT), is proposed in this paper. Furthermore, we also implement the proposed framework by using the WirelessHART standard. The results are compared to the classical time-triggered approach used in the IEC 61784-3-3 standard. The obtained results show that the proposed framework can reduce the bandwidth usage by 90% and support safety-critical applications that require a SFRT less or equal to 150 ms.

中文翻译：

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Safe-WirelessHART：一种新型框架，可在工业WSN上实现安全关键型应用

工业无线传感器网络（IWSN）主要用于监视应用程序，但是最近对控制和安全应用程序产生了兴趣。IEC 61784-3-3标准已经规定了开放式传输系统中的功能安全和通信。该标准基于循环轮询机制，该机制会消耗大量带宽。由于现有的IWSN的资源非常有限，因此这成为一项重大挑战。为了克服这个问题，本文提出了一种新颖的框架，该框架使用基于事件触发的故障安全机制，该机制基于同步有线轮询和无线时隙时分多址访问。对于安全关键型应用，我们分析得出最重要的度量标准的最小和最大界限，即安全功能响应时间（SFRT）。一个新的指标 本文提出了正常状态中断时间（NSIT）。此外，我们还通过使用WirelessHART标准来实现建议的框架。将结果与IEC 61784-3-3标准中使用的经典时间触发方法进行比较。获得的结果表明，提出的框架可以将带宽使用减少90％，并支持要求SFRT小于或等于150 ms的安全关键型应用程序。