EnDat2.2协议

【实例简介】
EnDat2.2协议的英文介绍，全称EnDat Interface VERSION 2.2，Bidirectional Synchronous-Serial Interface forPosition Encoders，适用于光电编码器，是德国海德汉公司为光电编码器开发的数据传输协议。
3.54 Version 55 3.5.5 Memory Partitioning of EnDat 2.1 3.5.6 Transfer format for position values 58 3.5.7 Encoder Type 58 3.5.8 Signal Period Length or Signal Periods per Revolution 59 3.5.9 Number of Distinguishable Revolutions 3.5.10 Increment of Reference marks 60 3.5.11 Position of the first reference mark 62 3.5.12 Measuring Step or Measuring Steps per Revolution Datum Shift of the encoder manufacturer 3.5.14 ID Number 3.5.15 Serial Number 68 3.5.16 Rotational direction 69 3.5.17 External configuration Diagnostics 69 3.5.18 Maximum Permissible Mechanical Velocity or Shaft Speed 3.5.19 Accuracy with Respect to Linear or Rotational velocity 3.5.20 Support of Error Messages 1 3.521 Support of Warnings 73 3.522 EnDat Command set/Applications 3.5.23 Measuring Length 74 3.5.24 Maximum Processing Time 3.5.25 EnDat Ordering Designation 76 3.5.26 CHECKSUM 3.6.1 Datum shift 8|362 Diagnostics Configuration 80 3.6.3 Address assignment 3.6.4 Instructions O0Ecoooag 3.6.5 Trigger Threshold of the Warning Bit for EXcessive Temperature 366 Cycle Time 88 3.10.1 Overview of parameters of the encoder manufacturer for endat 2.2 3.10.2 Status of additional information 1 3.10.3 Status of additional Information 2 3.10.4 Status of additional functions 85 3.10.5 Acceleration 85 3.10.6 emperature 86 3.10.7 Diagnostic Status 3.108 Support of Error Messages 2 86 3.109 Forced Sampling status 3.10. 10 Measuring Step or Measuring Steps per Revolution of Position Value 2 88 3.10. 11 Accuracy with Respect to Linear or Rotational velocity 89 3.10. 12 Number of Distinguishable Revolutions for Position value 2 3.10.13 Direction of rotation or traverse for position value 2 3. 10.14 Encoder ldentification 3.10. 15 Support of Instructions 95 3.10. 16 Maximum Permissible Encoder Temperature 95 3. 10.17 Maximum Permissible Mechanical Acceleration 95 3.10. 18 Number of blocks for Section 2 Memory Area 96 3.10.19 Maximum Clock Frequency 96 3. 10.20 Number of Bits for Position Comparison 3.10.21 Scaling factor for Resolution 97 Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 3/ Dae03072007030720071907207 Document no 131 3.10.22 Measuring Step, or Measuring Steps per Revolution or Subdivision Values of a Grating Period 97 3.10.23 Maximum Speed or RPM for Constant Code value 98 3.10.24 Offset Between Position value and Position value 2 3.10. 25 Number of Distinguishable Revolutions"with Scaling Factor 100 3. 10.26 Support of Operating Status Error Sources 101 3.10.27 CHECKSUM 101 4.2.1 Error Handling for Type I 105 4.2.2 Error Handling for Type 4.2.3 Error Handling for Type Ill 105 4.4.1 Hardware CRC Generation 107 4.4.2 Software CRc generation 108 o0兰E50009 Figure 1 Figure 2 8 Figure 3 8 Figure 4 Figure 5 1, 10 Figure 6 10 Figure 7 Figure lg 12 Figure 9 12 Figure 10 12 Figure 11 14 Figure 12 14 Figure 13 ■重日,日1,11d 15 Figure 14 Figure 15 15 Figure 16 Figure 17 16 Figure 18 Figure 19 :::..::::: 22 Figure 20 23 Figure 21 24 Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 4/ Dae03072007030720071907207 Document no 131 Figure 22 25 Figure 23 D面重 26 Figure 24 27 Figure 25 重 29 Figure 26 :.:::::日1 ■重日重重日,重重 31 Fiqure 27 ..32 Figure 28 35 Figure 29 35 Figure 30 36 Figure 31 36 Figure32… …37 Figure 33 37 Figure34....…… 38 Figure 35 39 Figure 36 39 Figure 37 40 Figure 38 40 Figure 39 :::::::::::: 41 Figure 40 41 Figure 4 1 .42 Figure 42 42 Figure 43 53 Figure 44 53 Figure 45 53 Figure 46 54 Figure 47 59 Figure 48 61 Figure 49 61 Figure 50 65 Figure 51 65 Figure 52 66 Figure 53 Figure 54 78 Figure 55 79 Figure 56 89 Figure 57 105 Figure 58 105 Figure 59 107 A Seealsowww.endat.de Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 5/ Dae03072007030720071907207 Document no 131 The interface described in this document is designed for and th such as numerical controls, servo amplifiers and programmable logic controllers. It offers the following benefits Permits the use of absolute encoders and incremental encoders Minimizes transmission time for the position value. In applications in closed control loops this reduces dead time and improves the control characteristics Because the interface is on demand (simplifies commissioning) Supports and of the subsequent electronics the values are always transferred in This means that the subsequent electronics always perform the same type of evaluation Gray code, PRC code, multiple incremental tracks with defined differences in the grating period, etc. The absolute position value has no sign Safety-relevant systems can be set up A Compatibility with EnDat 2. 1 is a subset of the command set for En Dat 2.2 Encoders with EnDat version 2.2 can be used as replacements for encoders with EnDat version 2.1 If there are any deviations, they are described in the specifications EnDat 2. 1 replacement units can also possibly have the EnDat 2.2 command set o0兰E50009 Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 6 Dae03072007030720071907207 Document no 131 Bidirectional data transfer(measured values or parameters)between position encoders and subsequent electronics is performed with transceiver components in accordance with differential signals), synchronous to the clock signal(CLoCK )produced by the subsequent electronics. Additionally to the serial data transmission, the encoder can provide that can be evaluated by the subsequent electronics. They have a See the encoder,s specifications to see whether it supports additional sinusoidal incremental signals. For special encoders that support the mode command Encoder to receive communication command, see document D385768 sheet 1 for the required receiver hardware Motor or machine housing Subsequent electronics Encoder optional Rnr? A+B+ Rn/2A-,8- C1C Data ↓如0 > Data input o0兰E50009 Bidirectional Data output serial data Clock 十} Clock OW Figure Ra< 100 Ohm Zo=120 Ohm Ca≤50pF U1≈Uo ∑|a<1mA RS 485 transceiver Uo=2.5y±0.5y C2=330pF The capacitors c1, c2 and c3 serve to improve the noise immunity A The propagation times vary between the serially transferred data and the additional incremental signals. These differences depend on the encoder and the characteristics of the transmission path A separate receiver/driver module is to be assigned to each encoder in safety-oriented applications The maximum permissible clock pulse frequency depends upon the cable length and the subsequent electronics. There are two basic versions of the subsequent electronics Without delay compensation With delay compensation Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 7 Dae03072007030720071907207 Document no 131 The IS 「he and the e between the encoder and the subsequent electronics The following diagram shows the maximum permissible clock pulse frequency f with respect to the cable length Lx between the encoder and the subsequent electronics at an on-off ratio of 1: 1 on the clock line 100 16000 kHz Maximum perm ssible clock frequency fr 。 Figure 2 9 For other on-off ratios, fo-2t min where the following applies to tmin 0 es No Clock Figure 3 Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 8/ Dae03072007030720071907207 Document no 131 With long cable lengths and high clock pulse frequencies, the propagation time over the transmission path becomes great enough that it must be compensated for in order to ensure clear data assignment Compensation is realized by determining the propagation time and taking it into account when the subsequent electronics evaluate the data. Temperature fluctuations must have no influence on the propagation time. This makes a maximum clock pulse frequency of 8 MHz possible, regardless of the cable length(maximum: 100 m) The clock frequency range of 8.. 16 MHz is intended for special applications 300 2000 4000 8000 12000 16000 o0兰E50009 Maximum perm ssible Clock frequency f Figure 4 Pay attention to the attenuation and transmission behavior The description refers to standard applications with a clock frequency of max 8 MHZ The propagation time must be determined with a decreased clock pulse frequency(100 kHz to 200 kHz) after every hardware change in the transmission path This step must be performed automatically after each power interruption. In order to achieve a satisfactory accuracy for the propagation time to(data delay time ) you must scan with a significantly higher internal frequency than the maximum clock pulse frequency intended for later data transmission For every rising clock pulse edge after the Encoder to send position values" mode command and after the transceiver has finished switching the encoder to sending, i.e. after every 10 clock pulse periods t, a counter must be started in the subsequent electronics the value of the counter must be saved with every rising clock pulse edge of the start bit. This process should be repeated at least three times and consistency should be checked, in order to exclude interferences while determining the propagation time To ensure clarity in the following pulse diagrams, only the noninverted signals are shown Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E Dae03072007030720071907207 Document no 131 ock frequenc1kz200k区 -nnmmnnrndn Encoder clock 凵凵凵凵山凵凵凵凵凵凵山L中凵凵山凵凵凵山凵凵凵凵 Encoder do ta )X00111x2 Starl Err 1 Dala::Data Data 0ato X CR XER TRC XCR Subsequent electronics data X000111 Star Em 1 Dato x::Data COta DOID)IRO CRD CRCCRC CROC start counter gure Clock 13 data bit Figure 6 The frequency fe for determining the propagation time tp must be at least eight times greater than the oOO0 maximum clock pulse frequency fc that is intended for later data transmission In order to ensure an accurate and interference-free value determination, the frequency for determining the propagation time can vary by a maximum of +10% Example EO9 Maximum clock pulse frequency for later data transmission fc 4 MHz>frequency fe for determining the propagation time tp= 4 MHz X 8=32 MHz; frequency tolerance +3.2 MHz This measurement must be carried out at least three times and an arithmetic mean must be found. to guarantee an unambiguous allocation of the data bits, the three measured values may not vary from the determined mean by more than 1/8 of the period of the maximum clock pulse frequency fc Release No ResponsibleReleased Version Rev. Sheet Page Name Lechner A. Strasser E. Strasser E 10 Dae03072007030720071907207 Document no 131 【实例截图】
【核心代码】