SAE J2716_20160429 (SENT协议).pdf

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SAE INTERNATIONAL J2716™ APR2016 Page 2 of 120

2.1.1 SAE Publications ........................................................................................................................................................ 6

2.1.2 Other Publications ...................................................................................................................................................... 6

3. DEFINITION OF TERMS ........................................................................................................................................... 6

3.1 Glossary ..................................................................................................................................................................... 6

3.2 Overview of SENT standard structure ....................................................................................................................... 8

4. ACRONYMS, ABBREVIATIONS, AND SYMBOLS ................................................................................................. 10

5. SENT SYSTEM REQUIREMENTS .......................................................................................................................... 10

5.2.5 Checksum Nibble ..................................................................................................................................................... 17

5.2.6 Pause Pulse (Optional) ............................................................................................................................................ 17

5.3 Transmission and Reception of Message ................................................................................................................ 18

5.3.1 Transmission of Message ........................................................................................................................................ 18

5.3.2 Adjustment of Received Message Nibble Lengths .................................................................................................. 18

5.3.3 Received Message Diagnostics ............................................................................................................................... 19

5.3.4 Reset ........................................................................................................................................................................ 21

5.4 Checksum Nibble Details ......................................................................................................................................... 21

5.4.1 Errors Detected and Not Detected by Checksum .................................................................................................... 21

5.4.2 CRC Implementation ................................................................................................................................................ 24

6.3.1 Transmitter Driver Requirements ............................................................................................................................. 27

6.3.2 Receiver Input Requirements................................................................................................................................... 33

6.3.3 Bus Wiring Harness and ECU Connectors .............................................................................................................. 35

6.4 ESD Immunity .......................................................................................................................................................... 35

6.5 EMC Testing Requirements ..................................................................................................................................... 36

6.6 Fault Protection Modes ............................................................................................................................................ 36

7. CONFIGURATION SHORTHAND ........................................................................................................................... 36

7.1 Shorthand Definition ................................................................................................................................................. 36

SAE INTERNATIONAL J2716™ APR2016 Page 3 of 120

Appendix D Serial channel message IDS ................................................................................................................ 58

Appendix E Common sensor definitions .................................................................................................................. 76

Appendix F Fast channel multiplexing ..................................................................................................................... 93

Appendix G SENT connectors ............................................................................................................................... 101

Appendix H SENT data frame formats ................................................................................................................... 103

Appendix I Alternative receiver circuit .................................................................................................................. 118

Figure 3.2.1-1 SENT standard structure and transmission layers ................................................................................. 9

Figure 5.2.1-1 Example encoding scheme for two 12 bit signals ................................................................................ 11

Figure 5.2.3-1 Example nominal nibble times .............................................................................................................. 12

Figure 5.3.2-1 Quantisation of sampled and calibrated nibble .................................................................................... 18

Figure 5.3.3.1-1 Error pattern for successive calibration pulse detection ....................................................................... 19

Figure 5.3.3.1-2 Successive calibration pulse detection ................................................................................................. 20

Figure 6.2.1-1 Illustration of clock error accumulation as given in table 6.2.1-1. ......................................................... 26

Figure 6.3-1 Example SENT system interface circuit topology ................................................................................. 27

Figure 6.3.1-1 Example SENT shaped waveform transmitter output .......................................................................... 28

Figure 6.3.1-2 SENT transmit pulse parameters ......................................................................................................... 28

Figure 6.3.1-3 SENT system interface circuit topology for a regulated 5v power supply of the transmitter by

the receiver ........................................................................................................................................... 30

Figure 6.3.1-4 SENT system interface circuit topology for an independent 5v power supply in the receiver with

Figure C.1.2.1-1 Error time examples ............................................................................................................................. 55

Figure C.1.2.2-1 Worst case age for signal as received by ECU .................................................................................... 56

Figure C.2-1 Supply current ripple test setup ............................................................................................................ 57

Figure D.6-1 Example: serial message cycle with 14 messages (table D.6-1) is transmitted continuously.

Serial message cycle can be captured within 64 messages. ............................................................... 72

Figure D.7-1 Start-up phase of the sensor and the ecu ............................................................................................ 73

Figure E.2.1.1-1 Nominal characteristic function of a sensor (with 12-bit data values) .................................................. 78

Figure E.2.1.2-1 Partitioning of measurement data ranges and mapping onto SENT data values (for illustration) ....... 80

Figure E.2.2.1-1 Default temperature characteristic function (for illustration) ................................................................. 82

Figure E.2.2.2-1 High temperature characteristic function (for illustration) ..................................................................... 83

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SAE INTERNATIONAL J2716™ APR2016 Page 4 of 120

Table 5.4.1-2 Checksum missed detection rate, edge shift between two nibbles

(valid frames only, recommended implementation).............................................................................. 22

Table 5.4.1-3 Checksum missed detection rate, asymmetrical edge shift offset by 1 between two nibbles

(valid frames only, recommended implementation).............................................................................. 23

Table 6.2.1-1 Communication clock tolerance............................................................................................................ 26

Table 6.3.1-1 Transmitter driver requirements ........................................................................................................... 29

Table 6.3.1-2 Independent 5v powered transmitter requirements .............................................................................. 31

Table 6.3.1-3 Independent 5v supply high power transmitter additional requirements .............................................. 32

Table 6.3.2-1 General receiver input requirements .................................................................................................... 34

Table 6.3.2-2 Discrete receiver component values .................................................................................................... 35

Table A.6.2.1 Interpretation of n-bit temperature data ................................................................................................ 46

Table A.6.3-1 Overview of temperature sensor frame formats and protocols ............................................................ 47

Table A.6.3-2 Overview of temperature sensor frame formats and protocols using fast channel multiplexing .......... 48

Table B.1-1 Example 4-bit checksum calculations, legacy implementation ............................................................ 51

Table B.1-2 Example 4-bit checksum calculations, recommended implementation ................................................ 51

Table B.1-3 Example 4-bit crc calculation by polynominal division ......................................................................... 52

Table B.1-4 Example 4-bit crc verification by polynominal division ......................................................................... 53

Table B.2-1 Example checksum calculations, 6-bit crc ............................................................................................ 54

Table C.1.2.1-1 Number of wrong frames for error time ................................................................................................ 56

Table C.2-1 Supply current ripple test setup circuit parameters .............................................................................. 57

Table D.6-1 Example: sub-set of message ids that are used by a sensor within one serial message cycle ........... 72

Table D.8-1 Manufacturers codes ............................................................................................................................ 74

Table D.9-1 Transmission of ascii characters over $90 to $97: encoding example ................................................ 75

Table E.1.2-1 Examples: measurement data and signaling data regions of fast and supplementary channel data .. 76

Table E.1.3-1 Error indicators / specific messages / initialization message ............................................................... 77

Table E.2.1.2-1 Partitioning of the signal data space with default Y

Table E.2.1.4-1 Default Y

values ...................................................................................................................... 80

Table E.2.2-1 Overview of temperature transfer characteristic functions ................................................................... 82

Table E.2.2.1-1 Transfer function parameters for default linear temperature data channels ........................................ 82

SAE INTERNATIONAL J2716™ APR2016 Page 5 of 120

Table F.6.4-1 Data frames with free to use data ...................................................................................................... 100

Table G.1.1.1-1 SENT connector termination assignment ........................................................................................... 101

Table H-1 Basic SENT frame formats, data channels and nibble orders ........................................................... 104

Table H-2 Allocation of the bits of the status and communication nibble ............................................................ 104

Table H.1-1 Nibble and bit orders for sensors with two 12-bit fast channels ......................................................... 106

Table H.3.1-1 Nibble and bit orders for high-speed 12-bit sensors........................................................................... 109

Table H.5-1 Nibble and bit orders for single sensors with one 12-bit fast channel ................................................ 112

Table H.6-1 Nibble and bit orders for sensors with 14-bit fast channel 1 and 10-bit fast channel 2 ...................... 114

Table H.7-1 Nibble and bit orders for sensors with 16-bit fast channel 1 and 8-bit fast channel 2 ........................ 116

Table I.1-1 Allowed pulse shape deviation between reference receiver and alternative circuit ........................... 118

1. SCOPE