To meet the demand for more reliable sensory data, longer sensor calibration cycles, and more useful information for operators at NASA's Kennedy Space Center (KSC), NASA's Instrumentation Branch and ASRC's Advanced Electronics and Technology Development Laboratory at the KSC are developing custom intelligent sensors based on the IEEE 1451 family of smart-sensor standards. The KSC intelligent sensors are known as Smart Networked Elements (SNEs), and each SNE includes transducers and their associated Transducer Electronic Data Sheets (TEDS), signal conditioning, analog-to-digital conversion, software algorithms for performing health checks on the data, and a network connection for sending data to other SNEs and higher-level systems. The development of the SNE has led to the definition of custom architectures, protocols, IEEE 1451 implementations, and TEDS, which are presented in this paper. The IEEE 1451 standards describe the architecture, message formats, software objects, and communication protocols within the smart sensor. Because of the standard's complexity, KSC has simplified the IEEE 1451 architecture and narrowed the scope of software objects to be included in the SNE to create a "light" IEEE 1451 implementation, and has used the manufacturer-defined TEDS to customize the SNE with health indicators. Furthermore, KSC has developed a protocol that allows the SNEs to communicate over an Ethernet network while reducing bandwidth requirements.