M-bus协议解释.pdf

【核心代码】

1 Introduction .......................................................................................................................... 3
2 The Basics of Serial Bus Systems........................................................................................ 4
2.1 Applications and Definitions .......................................................................................... 4
2.2 Basic Functions of Bus Systems..................................................................................... 5
2.2.1 Access Techniques ............................................................................................... 6
2.2.2 Synchronization of Participants........................................................................... 7
2.2.3 Error Processing ................................................................................................... 7
2.3 The OSI Reference Model .............................................................................................. 8
3 Overview of the M-Bus...................................................................................................... 11
3.1 Requirements of a Bus System for Consumer Utility Meters....................................... 11
3.2 The M-Bus in the OSI Model........................................................................................ 11
4 Physical Layer .................................................................................................................... 14
4.1 Principles of Operation ................................................................................................. 14
4.2 Specifications for Bus Installations............................................................................... 16
4.3 Specifications of the Repeaters..................................................................................... 17
4.4 Slave Design ................................................................................................................. 17
5 Data Link Layer ................................................................................................................. 21
5.1 Transmission Parameters .............................................................................................. 21
5.2 Telegram Format........................................................................................................... 22
5.3 Meaning of the Fields ................................................................................................... 23
5.4 Communication Process................................................................................................ 25
5.5 FCB- and FCV-Bits and Addressing............................................................................. 27
5.5.1 Applications of the FCB-mechanism .................................................................. 27
5.5.2 Implementation aspects for primary addressing .................................................. 28
6 Application Layer............................................................................................................... 31
6.1 CI-Field ......................................................................................................................... 31
6.2 Fixed Data Structure ..................................................................................................... 34
6.3 Variable Data Structure................................................................................................. 36
6.3.1 Fixed Data Header.............................................................................................. 36
6.3.2 Variable Data Blocks.......................................................................................... 37
6.3.3 Manufacturer Specific Data Block ..................................................................... 43
6.4 Configuring Slaves........................................................................................................ 45
6.4.1 Switching Baudrate............................................................................................. 45
6.4.2 Writing Data to a Slave ...................................................................................... 46
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6.4.3 Configuring Data Output.................................................................................... 48
6.5 Generalized Object Layer.............................................................................................. 51
6.6 Application Layer Status............................................................................................... 53
6.7 Special Slave Features .................................................................................................. 55
6.7.1 Auto Speed Detect.............................................................................................. 55
6.7.2 Slave Collision Detect........................................................................................ 56
6.7.3 Use of the Fabrication Number .......................................................................... 57
6.7.4 Hex-Codes $A-$F in BCD-Data Fields............................................................... 57
7 Network Layer.................................................................................................................... 63
7.1 Selection and Secondary Addressing ............................................................................ 63
7.3 FCB-Bit and Selection .................................................................................................. 64
7.4 Searching for Installed Slaves...................................................................................... 65
7.4 Generalized Selection Procedure .................................................................................. 69
8 Appendix ............................................................................................................................. 70
8.1 Alarm Protocol.............................................................................................................. 70
8.2 Coding of Data Records................................................................................................ 71
8.3 Tables for Fixed Data Structure .................................................................................... 74
8.3.1 Measured Medium Fixed Structure .................................................................... 74
8.3.2 Table of Physical Units....................................................................................... 75
8.4 Tables for Variable Data Structure ............................................................................... 76
8.4.1 Measured Medium Variable Structure ............................................................... 76
8.4.2 Data Field Codes ................................................................................................ 77
8.4.3 Codes for Value Information Field (VIF)........................................................... 78
8.4.4 Extension of primary VIF-Codes........................................................................ 80
8.4.5 Codes for Value Information Field Extension (VIFE) ....................................... 84
8.5 References..................................................................................................................... 88