ABSTRACT The SAE J2716 SENT (Single Edge Nibble Transmission) Protocol has entered production with a number of announced products. The SENT protocol is a point-to-point scheme for transmitting signal values from a sensor to a controller. It is intended to allow for high resolution data transmission with a lower system cost than available serial data solution. The SAE SENT Task Force has developed a number of enhancements and clarifications to the original specification which are summarized in this paper. The most significant updates include the following: • Adding an optional pause pulse which can make the frame length independent of the SENT message data content • Defining a new enhanced serial message encoding as an optional replacement for the original short serial data message • Clarifying the diagnostics and remedial actions for successive calibration pulse comparisons • Adding recommended processing of a zero nibble in addition to the data in the checksum calculation to protect against a common error in the last data nibble and checksum • Adding a new recommended circuit topology to better support 3.3V receiver systems• Updating specification of data formats and protocols for mass air flow (MAF), Temperature and Pressure applications. • Adding new communication protocols to take advantage of the new Enhanced Serial Message • Adding EMC Susceptibility testing guidelines INTRODUCTION The SAE J2716 Task Force, under the SAE Vehicle Architecture for Data Communications Committee, has developed the SENT (Single Edge Nibble Transmission) sensor signaling protocol. The Task Force has issued two SAE Information Reports detailing the specification [ 1, 2] with a third release published in 2009 [ 3]. The original design was documented in SAE paper 2005-01-1366 [ 4]. The SENT protocol is a point-to-point scheme for transmitting signal values from a sensor to a controller. It allows for high resolution data transmission and multiplexing of multi-mode data with higher bandwidth and accuracy versus other point-to-point technologies such as ADCs, PWMs and frequency modulation. It also may be considered as a potential competitor in low cost applications for other protocols such as CAN, LIN and PSI5. A number of production parts (see for example [ 5, 6, 7, 8]) and application notes (see for example [ 9, 10, 11]), have been J2716 SENT - Single Edge Nibble Transmission, Updates and Status2011-01-1034 Published 04/12/2011 Mark Costin and Robert Horner General Motors Company Johannes Jaegers Hella KGaA Hueck & Co Dirk Daecke, Alex Grossmann and Bernhard Opitz Robert Bosch GmbH Machiel ten Brinke, Tim Tiek and Eric Visser Sensata Technologies Copyright © 2011 SAE International doi:10.4271/2011-01-1034Downloaded from SAE International by Univ of California Berkeley, Monday, July 30, 2018created using the J2716 protocol. Feedback from these designs as well as new application enhancements, have been incorporated by the SAE J2716 SENT Task Force into the latest specification release. This paper details these changes; the most significant include the following: • Adding an optional pause pulse which can make the frame length independent of the message data content • Defining a new enhanced serial message encoding as an optional replacement for the original short serial data message. The new data format and protocols for serial messages allow numerous new features of SENT sensors. • Clarifying the diagnostics and remedial actions for successive calibration pulses comparisons • Adding a recommended change to the 4-bit checksum calculation of the cyclic redundancy check for error detection. The recommended checksum calculation includes processing a zero nibble in addition to the data nibbles to protect against a common error in last data nibble and checksum. The original CRC method is retained as an option for designs already in process or production that were developed according to previous SENT norms. • Adding a new recommended circuit