RV-C Revised Application Layer.pdf

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北美房车大量采用的一种基于CAN2.0的通讯协议,可广泛的使用在房车各种设备之间的通讯,是房车领域主流的通讯协议
C RVIA RV-C 3 500m <10018AWG 500m <10016AWG effectively equivalent to creating a Zero-length drop. this technique may be mixed with ordinary drops if desired S.This is A"daisy chain"topology may be simulated if every node has an input and an output connection for the can signals Both ends of the bus shall be terminated with a 120-ohm resistor 2.1.3 Data rate, signal levels and slope The data rate for all transmitters shall be 250 kbit/s the sample point shall be in the range of 85%to 90%of the bit-time (recommended location or the sample point is 3. 5 us). The signal levels are specified in 2.1.3 Table 2.1.3: Signal level State Voltage Dominant CAN H=3.5V. caN L=1.5V Vdiff=2.0V Recessive CAN H=2,5V. can L=2,5V Vdiff=0.0V practice creates unacceptable interoperability challenges and should be avoided ne bit rise and fall times to reduce EMl. this NOTE Some Can transceivers provide options for"slope control", which slows 2.1.4 Connectors Network cable conductors shall be spliced or tapped and properly joined with connectors, pressure connectors or by soldering Individual conductor insulation displacement attachments are not recommended. This protocol recommends that suggested connectors be used for the network trunk. a list of suggested connectors follows for the network trunk in Table 2.1.4a, but designers are free to use connectors according to their utility in their specific application. All trunk connectors should use standardized pin-out convention listed in Table 2.1. 4a except for established circular connectors. If the standard pin-out convention is not used then the equipment or connectors must be labeled with the pin-outs used. The chassis routing should only use sealed connectors and the interior may use sealed or unsealed connectors. Connections to the network trunk cable should be direct or short drop cables connecting to network devices and should use connectors appropriate to the device manufacturers products. Table 2.1. 4b shows recommended trunk connectors Table 2.1. 4a -Connector standard pin- out convention PIN DESCRIPTION 1 ora CAN-H 2 or b CAN-L 3 or c (or SHIELD) OPTIONAL 4 or d PS+ OPTIONAL 5 or e SHIELD OPTIONAL OTHER(S) OPTIONAL Unless labeled or documented otherwise Table 21. 4b trunk connectors RV-C Connector recommendations Figure CONNECTOR PINOUTS December 17. 2015 2.1.4-Connectors C RVIA RV-C ANH|As咚| ShieldN.C. SEALED Automotive style 2 pin 2.1.4a1 (Requires external network ground) Automotive style 3 pin 2.1.4bA B Requires external network ground Automotive style 4 pin 214c1 (Allows power over network) Allows power over network)e Automotive/Marine/rv blade st 214d1 3 SEALED MARINE Circular Industrial/ Marine style 5 pin 2.14e Allows power over network) UNSEALED Pn& Socket0.165”4pin 214f1 (Allows power over network) The end views are the mating sides of the connectors PLUG RECEPTACLE 21 [41.|5 12 [6.54 |2.011 Figure 2. 1.45 RECEPTACLE PLUG AAFB B NOd/c c Fiqure 2.1 41 December 17. 2015 2.1.4-Connectors C RVIA RV-C RECEPTACLE PLUG Figure 2.1.4c g RECEPTACLE PLI 46 18. 9/ REF 2.120 2 Figure 2.1.4d RECEPTACLE PLUG Fiqure 2.1. 4e PLUG RECEPTACLE 3 啦4,4 2) 中22岁世 (9.60) 65 (4.20) Figure 2.1.4f December 17.2015 2.1.4-Connectors C RVIA RV-C 2,15 Environmenta/ standards The definition of environmental features such as temperature EMl, vibration et cetera is not in the scope of this document 2.2 Diagnostic Connector A recreation vehicle equipped with a rv-c network shall be equipped with a standard connector specifically for the attachment of diagnostic tools. The connector shall be from the amp circular plastic connector(CPC) series, with 9 pins. A typical member designed for bulkhead mounting is Amp 206705-01 as shown in Figure 2.2. Any exact mechanic equivalent is acceptable Figure 2.2-Diagnostic connector Table 2.2 defines the pin assignments Table 2.2-Pin assignment Pin Description Power(12 VDC). This may be tapped by the diagnostic tool. reserved reserved reserved ground reserved Shield(optional) RV-C data (+) (CAN_H RV-C data() (CAN-- 2. 3 Network Power Network power may be supplied over the network cable. Low power devices may be operated on network power within specified limits a)Devices must operate over the minimum voltage range of 9.0 to 16.0 Vdc that use the network cable power b) Device current not to exceed 200mA per node supplied from network cable power source c)Maximum current per conductor over network trunk cable according to wire gauge and network bus length shall not exceed in Table 2. 3 and must comply with"ANSI/RVIA Standard for Low Voltage Systems in Conversion and Recreational vehicles d) Network devices operating on network power shall be electrically isolated and not connect Ps-to rv ground e)Network devices and power supplies shall not degrade network performance and may not introduce noise, ripple or transients excess of 250mVpp with a frequency of greater than 1 Hz and up to 15vpp allowed with a frequency of less than 1 Ha f)Network power supplies shall limit the current per conductor size and length not to exceed the values in table 9.1 g) Network power supplies shall have a nominal output voltage of 12.5 vdc h) Network power supplies shall be able to be paralleled if current limited to fractions of the maximum network current capacity Multiple power sources should be current mode outputs with a maximum voltage range of 12.5 +/-3.5 Vdc Paralleled power December 17. 2015 23- Network power C RVIA RV-C supplies total currents shall not exceed the current in table 2. 3 O Network power supply source(s)must bond PS-to Rv chassis ground at power supply with a least 18 AWG wire or equivalent Table 2.3- Total current over network cable for length(10% voltage drop per 12V conductor Gauge / Current 0. 25 amp 0.5 amp1 2 amps 3 amps 4 amps 5 amps 24 AWG 56m 28m 14m 22 AWG 89m 44m 2m 20 AWG 141m 70m 35m 18m 12m 18 AWG 225m 112m 56m 28m 19m 14m 11m 16 AWG m 79m 89m 45m 30m 22m 18m Denotes not acceptable December 17.2015 23- Network power C RVIA RV-C 3 Intermediate Layers 3.1 Data frame structure Messages shall use only can data frames in extended frame format with a dlC of 8. CAN remote frames shall not be used Figure 3. 1 shows the structure of the can data frame in extended frame forma Figure 3. 1 can data frame structure Arbitration field Control field Data field CRC field ( base)ID (extended)ID DLC Sequence CDN E MSB(first bit transmitted 3.2 Network and Transport Layers The network, transport, and application layer protocols shall use the base and extended id field as well as the data field of the CAN data frame. The network, transport, and application layer message structure is defined in 3.2 Table 3. 2: Structure of the network, transport, and application layer message DLL fields RV-C name Description Name Bit (abbreviation) 111b- Lowest priority 28 to 26Priority 000b-Highest priority Base d Reserved Always 0b 24to18 Identifies how the data packet should Data Group Number 17 and 16 High be parsed, possibly in combination with the dgn-low Either determines the target node for Extended Data Group Number- the message, or with the DGN-High D 15to8 LOW determines how the data packet should )e parse 7 to 0 Source address(SA) Shall be unique for each node Defined in detail in the rv-c application Data 64to0 Data profile specification Due to the bus arbitration method used in the can data link layer protocol the use of the priority bits and the Sa bits are limited When two RV-C nodes attempt to transmit simultaneously, the priority bits determine which message will get on the bus first. All RV-C nodes shall have a unique source address, which is the tiebreaker-of-last-resort The network, transport, and application layer protocol demands that all rv-c nodes respond to certain messages. All messages December 17. 2015 3.2-Network and Transport Layers C RVIA RV-C on the network shall conform to this specification 3,2,1 Source addresses 3, 2.1.1 Introduction Every RV-C node shall have a unique source address to serve as a final tiebreaker during bus arbitration The source address does not fully identify the rv-c node and shall not be used by other Rv-c nodes to interpret data from that node, except in matters of address claiming, proprietary messaging, and diagnostics Source addresses shall be assigned in one of two ways. Rv-C node designers may choose to "hard wire"a standard address for the particular RV-C node type as defined in clause 3.2.1.2. Integrators shall take care to ensure that no two RV-C nodes using this technique are installed with the very same address A designer seeking greater flexibility may use the address claiming procedure, which dynamically assigns an SA when the RV-C node is powered up. The procedure is described in clause 3.3 3.2.12 Predefined source addresses A list of Rv-C node types, the recommended static SA assignment and the starting SA for dynamic SA assignment( node claiming procedure)is given in Table 7.2 3.2.2 Data group number The dgn identities uniquely the parameter group. The data group is a set of signals that are transmitted in the same network, transport, and application layer message. The dgn shall be a 17-bit value that shall be built from the bits in the extended data from as indicated in table 3.2 NOTE All data will be explicitly assumed to have a single source, which is explicit in the assigned DGN. A common example of a datum that may have many sources is "DC system voltage". This reading may come from the battery charger, inverter, system monitor, and even from other components that have an analog-to-digital converter with a spare channel. But the protocol does not support the concept of a global "System voltage".Instead, each RV-C nodes may transmit the DC Voltage as part of one of the DGNs it transmits. There is no DC system voltage"-only DC Voltage Refrigerator", DC voltage Inverter #1, and so 3.2.3 Data type definitions The data field contains one or more signals or parameters For each signal or parameter the type of data is assigned Alphanumeric data shall be transmitted with the most significant byte first; other data consisting of 2 or more byte shall be transmitted least signiticant byte first Within the byte the bits are transmitted most significant bit first as shown in Table 3.2.3a Table 3. 2. 3a Transfer syntax for bit sequences Byte 0 Byte 1 Byte n(n=2 to 7) b7 to bo b15 to b8 b8n-1 to b8n-8 The value ranges and value definitions for the data types are defined in Table 3. 2. 3b Table 3. 2.3b- Sstandard data types Description Range Si ze Type Value definition Bit field 0 to 1 2 bit bit 11b- Data not available 10b- Error 01b-On December 17.2015 3.2.3-Data type definitions ⊙RWA RV-C Description ange Size Type Value definition 00b-Off Character 1to253 1 byte char 255-Data not available 254-Out of range 0-Reserved Floating point, Variabl 8 byte float647FFF FFFFFFFF FFFFh-Data not available lEEE 754 double 7FFF FFFF 杆F FFFEh-Out of range precIsion 7FFF FFFF FFFDh -Reserved Floating point,Variable 4 byte float32 7FFF FFFFh-Data not available EEE 754 single 7FFF FFFEh -Out of range precision 7FFF FFFDh -Reserved Integer, 16 bit 0 to 65532 2 byte uint1665535-Data not available unsigned 65534-Out of range 65533-Reserved NotE LSB first Integer, 32 bit 2's-2147483, 648 4 byte int322147483647-Data not available complement to 2147483646-Out of range +2147483644 2147483645- Reserved note LSB first Integer, 32 bit 0 to 4 byte uint324294967295-Data not available unsigned 4294967292 4294967294-Out of range 4294967293- Reserved NotE LSB first Integer, 8 bit 0 to 252 1 byte uint8 255-Data not available 254-Out of range 253- Reserved 3.2.4 Network, transport, and application layer message types 3.2.4.1 nformation sharin Most RV-C nodes have associated with them a set of data, which it broadcasts on the network. For example, a generator transmits data on it loading, fuel consumption, AC amperage and voltage, coolant temperature, and so on. To accomplish this, messages may be defined and dgNs assigned to these messages. All information sharing may be accomplished through these pre-formatted messages Information sharing messages are generally set at priority 6. Exceptionally, higher priorities may be used for time-sensitive data (such as data used in mechanical controls). Information sharing messages requiring more than 8 data bytes are distributed to several network, transport, and application layer messages. Even if the Rv-c node does not support every item in the packet, th entire packet shall be sent. Certain values are used to indicate that a particular datum is not supported or is not available at the moment Each RV-C node may have several messages associated with it. It is also possible that two rv-C nodes may"share"a message each may transmit different data items from the same group December 17. 2015 3.2.4.1-Information sharing

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