GB/T 37987-2019Specifications for application interface of read-write equipment for the electronic identification of motor vehicles (English PDF)

3.1 news

The smallest unit of information for interactive communication between a read-write device and other devices or systems.

3.2 parameter

The message is composed of a specified data type and sequence, and is a data sequence used to convey information.

3.3 Identification rules

The rules described by multiple sets of parameters that must be followed when the read-write device performs identification operations or read operations on the electronic identification of motor vehicles.

3.4 Access rules

The rules described by multiple sets of parameters that must be followed when the read-write device reads or writes the designated electronic vehicle identification.

3.5 Identifier

A mnemonic consisting of multiple characters used to identify a message or parameter.

5.1 Communication protocol

5.1.1 Ethernet communication

The communication protocol should meet the following requirements.

a) Support TCP protocol, the default communication port number is 5084;

b) Support the SSL application layer security communication protocol, which meets the requirements of Chapter 5 and Chapter 6 in GM/T 0024-2014;

c) Support HTTP application layer communication protocol, use the POST method defined in 4.3.3 in RFC7231 to send messages, use RFC Encoding is performed in the Base64 encoding method defined in 6.8 in 2045.

5.1.2 Serial communication

The communication protocol should meet the following requirements.

a) The communication frame is composed of 6 parts. frame header, source address, destination address, message, check code and frame end. The structure is shown in Figure 1.Part symbols

Meet the following requirements.

1) The frame header and frame end are hexadecimal data 0x7E;

2) The source address and destination address are represented by 1 byte respectively, which respectively identify the address code of the message sender and the address of the message receiver coding;

3) The message meets the requirements of 6.1;

4) Escape when the hexadecimal numbers 0x7E, 0x7D appear in the source address, destination address and message, the escape method is. 0x7E

Use 0x7D, 0x5E instead, 0x7D use 0x7D, 0x5D instead;

5) The check code uses CRC16, the generator polynomial is x16 x15 x2, and the initial value is 0xFFFF. Generating checksum

The verification range is the escaped source address, destination address and message data. If the hexadecimal number 0x7E appears in the check code,

When 0x7D is escaped, see 4) for the escape method.

b) When the communication interface is EIA-RS-232C, EIA-RS-485 interface, under default conditions. the communication bit rate is 19200bit/s, byte

The structure is 8 data bits, 1 stop bit, no parity bit, and no flow control.

Figure 1 Serial communication data frame

5.2 Interaction types, functional requirements and typical interaction procedures

5.2.1 Types of interaction

The interaction between the read-write device and other devices or systems is divided into communication link monitoring, read-write device operation rule management, read-write device management and

4 types of data reporting.

5.2.2 Functional requirements

5.2.2.1 Communication link monitoring

Communication link monitoring is used to establish and maintain communication links under Ethernet communication conditions.

5.2.2.2 Operation rule management of read-write equipment

Read-write device operation rule management is used for the configuration and maintenance of identification rules and access rules, and realizes the addition and maintenance of identification rules and access rules.

Query, delete and other operations.

5.2.2.3 Read and write device management

The read-write device management is used for the query and configuration of the basic attribute parameters of the read-write device, the monitoring of the running status, and the management of the program version.

5.2.2.4 Data reporting

Data reporting is used for reading and writing equipment to upload the electronic vehicle identification information read to other equipment or systems.

5.2.3 Typical interaction process

See Appendix A for the typical interaction process.

5.3 Exception handling

When both parties in communication receive a message that cannot be resolved, they should be discarded.

6.1 Message classification and composition

6.1.1 Classification

In the process of interactive communication between the read-write device and other devices or systems, messages are divided into non-response messages and response messages according to response modes.

Message processing should meet the following requirements.

a) If no response message is received, there is no need to feed back the processing result to the sender;

b) If a response message is received, the response message is sent to the sender and the processing result is fed back.

6.1.2 Composition

The message consists of a message header and a message body, and multi-byte data is transmitted in big-endian mode. Among them, the message header consists of the device serial number, version number,

It consists of 5 parts. message code, message length, and message number. The message composition structure is shown in Figure 2, and each part should meet the following requirements.

a) Device serial number. the serial number of the read-write device, the length is 64 bits, which can uniquely identify the identity of the read-write device.

b) Version number. The version number of the interface specification of the read-write device, the length is 8 bits, and the fixed value is 0x01.

c) Message code. the identification code of the message type, the length is 16 bits. See Appendix B for the definition of message identifier and identification code.

d) Message length. the number of bytes of the message body content, the length is 32 bits.

e) Message number. the sequence number of the message, the length is 32 bits, and the value starts from 1 for recycling. The message number and phase of the response message

The corresponding request message has the same message number.

f) Message body. It consists of one or more parameters, or it can be empty.

6.2 Parameter classification and requirements

6.2.1 Parameter classification

Parameters are divided into three types. simple parameters, array parameters and structure parameters.

6.2.2 Requirements

6.2.2.1 Simple parameters

Simple parameter. It is composed of one or more bits or bytes, and the data type is shown in Table C.1 in Appendix C.

6.2.2.2 Array parameters

Array parameters. It is composed of array length and array content, and should meet the following requirements (see Table C.2 in Appendix C for data types).

a) Array length. the number of simple parameters, the length is 32 bits;

b) Array content. a set of simple parameters of the same data type.

6.2.2.3 Structural parameters

Structure parameter. It consists of three parts. parameter code, parameter length and parameter content. For data types, see Table C.3.in Appendix C. Each part

Meet the following requirements.

a) Parameter code. the identification code of the parameter type, the length is 16 bits. Refer to Appendix D for the definition of parameter identifiers and identification codes.

b) Parameter length. the number of bytes of the parameter content, the length is 32 bits.

c) Parameter content. The specific value of the parameter is composed of one or more parameters.

6.3 Identifier

Message and parameter identifiers should meet the following requirements.

a) The identifier consists of uppercase letters, lowercase letters, numbers and special characters, and no spaces are allowed. Special characters include hyphens (_), asterisk (*) and plus sign () 3 types.

b) The message identifier starts with the string "M_" prefix.

c) Simple parameters and array parameters start with the string "D_" prefix.

d) The structure parameter identifier starts with the string "P_" prefix.

7.1 Link establishment response message

The message identifier is M_ConnectionAck, the link establishment response message, and the message body content is shown in Table 1.When the Ethernet port is used, the communication parties

Either party can establish a communication link according to the requirements of the TCP protocol. After the communication link is established, the reading and writing device should send this message to other devices or systems.

Table 1 Message body content of link establishment response

Serial number parameter identifier parameter data type parameter content

7.2 Heartbeat request message

The message identifier is M_Keepalive, the heartbeat request message has no message body content. When the Ethernet port is used, the

Send this message to other devices or systems at time t. Time t should be from 1s to the maximum random time set in Table E.2 (D_MaxTrig- gerValue) randomly generated within the value range.

7.3 Heartbeat response message

The message identifier is M_KeepaliveAck, the heartbeat response message has no message body content. Other devices or systems receive the

Send this message after the incoming heartbeat request message. When the heartbeat response message times out for 3 consecutive times, the communication link should be closed, and the

Initiate a new connection or wait for the other party to initiate a connection again.

7.4 Link disconnection request message

The message identifier is M_Disconnect, the disconnection request message, and there is no message body content. When either party needs to interrupt the communication link,

Send this message.

7.5 Link broken response message

The message identifier is M_DisconnectAck, the disconnection response message has no message body content. After receiving the disconnection request message, send to the other party

Send this message to confirm that the communication link is closed.

8.1 Identification rules

8.1.1 Rule generation

Other devices or systems send a request message for adding identification rules (M_AddSelectSpec), and the reading and writing device generates identification rules based on the request message.

8.1.2 Rule status

The status of the recognition rule is divided into three types. disabled, ready, and enabled. When the recognition rules are initially generated, the status should be disabled or ready.

8.1.3 State transition

The state transition of the recognition rule is shown in Figure 3.The state transition should meet the following requirements.

a) The identification rule in the disabled state, the read-write device receives the activation identification rule request message from other devices or systems

When requesting to activate the recognition rule, the recognition rule state jumps to the ready state.

b) The recognition rules in the ready state can be changed in the following ways.

1) Other devices or systems send a request message for enabling identification rules (M_StartSelectSpec) to jump to the enabled state;

2) When the conditions specified by the recognition rule enable trigger parameter (P_SelectSpecStartTrigger) are met, it will automatically jump to the enabled state;

3) Other devices or systems send a request message (M_DisableSelectSpec) to disable the recognition rule and jump to the disabled state.

c) The recognition rules in the enabled state can be converted in the following ways.

1) Other devices or systems send a stop recognition rule request message (M_StopSelectSpec) to jump to the ready state;

2) When the conditions specified by the recognition rule stop trigger parameter (P_SelectSpecStopTrigger) are met, it will automatically jump to the ready state;

3) Other devices or systems send a request message (M_DisableSelectSpec) to disable the recognition rule and jump to the disabled state.

8.1.4 Rule deletion

The reader/writer device deletes the corresponding recognition rule after receiving the request message (M_DeleteSelectSpec) for deleting the recognition rule from other devices or systems.

8.1.5 Data reporting requirements

When the reporting conditions set by the identification report rule parameter (P_SelectReportSpec) are met, the read-write device will report the address parameters according to the (P_ReportDestination) requires that the data be uploaded to other devices or systems through the designated communication link.

8.1.6 Message content

8.1.6.1 Add recognition rule request message

The message identifier is M_AddSelectSpec, and the request message for adding identification rules is shown in Table 2.

8.1.6.2 Add recognition rule response message

The message identifier is M_AddSelectSpecAck, add a recognition rule response message, and the content of the message body is shown in Table 3.

Table 3 The content of the response message body for adding the recognition rule

Serial number parameter identifier parameter data type parameter content

1 P_Status P1 Message response parameter, return message execution result, see Table E.25 in Appendix E

8.1.6.3 Delete identification rule request message

The message identifier is M_DeleteSelectSpec, the delete identification rule request message, and the message body content is shown in Table 4.

8.1.6.4 Delete recognition rule response message

The message identifier is M_DeleteSelectSpecAck, delete the recognition rule response message, and the message body content is shown in Table 5.

8.1.6.5 Enable identification rule request message

The message identifier is M_StartSelectSpec, the request message for enabling identification rules, and the message body content is shown in Table 6.

8.1.6.6 Enable recognition rule response message

The message identifier is M_StartSelectSpecAck, the identification rule response message is enabled, and the message body content is shown in Table 7.

8.1.6.7 Stop Recognition Rule Request Message

The message identifier is M_StopSelectSpec, the stop recognition rule request message, and the message body content is shown in Table 8.

8.1.6.8 Stop recognition rule response message

The message identifier is M_StopSelectSpecAck, the stop recognition rule response message, and the message body content is shown in Table 9.

8.1.6.9 Activate recognition rule request message

The message identifier is M_EnableSelectSpec, the activation identification rule request message, and the message body content is shown in Table 10.

8.1.6.10 Activate recognition rule response message

The message identifier is M_EnableSelectSpecAck, the activation identification rule response message, and the message body content is shown in Table 11.

8.1.6.11 Disable recognition rule request message

The message identifier is M_DisableSelectSpec, a request message for disabling the identification rule, and the message body content is shown in Table 12.

8.1.6.12 Disable recognition rule response message

The message identifier is M_DisableSelectSpecAck, the identification rule response message is disabled, and the message body content is shown in Table 13.

8.1.6.13 Query recognition rule request message

The message identifier is M_GetSelectSpec, the query identification rule request message, there is no message body content.

8.1.6.14 Query recognition rule response message

The message identifier is the query recognition rule response message, and the message body content is shown in Table 14.

8.2 Access rules

8.2.1 Rule generation

Other devices or systems send request messages for adding access rules, and the read-write device generates access based on the request messages.

Ask the rules.

8.2.2 Rule status

The access rule status is divided into two types. disabled and ready.

8.2.3 State transition

The state transition of the access rule is shown in Figure 4.The state transition should meet the following requirements.

a) For the access rule in the disabled state, the read-write device receives the activation access rule request message sent by other devices or systems (M_EnableAccessSpec) When requesting to activate the access rule, the access rule status jumps to the ready state;

b) For the access rule in the ready state, the read-write device receives a request message for disabling the access rule sent by another device or system (M_DisableAccessSpec) then jump to the disabled state.

Cmd1.Add access rule request message (M_AddAccessSpec), and the message parameter "D_CurrentState" takes the value 0

Cmd2.Add access rule request message (M_AddAccessSpec), and the message parameter "D_CurrentState" is set to 1

Cmd3.Activate access rule request message (M_EnableAccessSpec)

Cmd4.Disable access rule request message (M_DisableAccessSpec)

Cmd5.Delete access rule request message (M_DeleteAccessSpec), or access rule parameter (P_AccessSpec) parameter value is 1 and the number of operations reaches the agreed number

Figure 4 Schematic diagram of access rule state transition

8.2.4 Rule deletion

Rule deletion should meet the following requirements.

a) For the access rules in the disabled state and ready state, the read-write device receives the delete access rule request from other devices or the system.

Delete the rule after requesting the message (M_DeleteAccessSpec);

b) When the stop trigger type in the access rule stop trigger parameter is set to 1, it stops according to the number of operations. The number of operations reached the agreed number

After the value, delete the rule.

8.2.5 Rule execution

Access rules should be associated with identification rules before they can be executed. Set access rule parameters (P_AccessSpec) to set one or more

The question rule is associated with the same recognition rule. The access rules execution steps are as follows.

a) After the read-write device executes the identification rules, select the execution order of the access rules in the ready state associated with the identification rules.

One access rule; if there is no access rule in the ready state, the access operation is ended;

b) The read-write device performs the identification matching rule parameter (P_HbMatchSpec) in the access rule on the read motor vehicle electronic mark

Identify the data for matching, if the matching succeeds, go to step d), otherwise go to step c);

c) Select the next access rule in the ready state in the order of the access rules bound to the recognition rule, and repeat the steps b); If there is no next access rule in the ready state, the access operation is ended;

d) According to the read access operation rule parameter (P_HbReadSpec) and write access operation rule in the access rule parameter (P_AccessSpec)

Then the parameters (P_HbWriteSpec) and the security module rule parameters (P_SecurityModuleSpec) enter the vehicle electronic identification

Row read operation or write operation, after the rule is executed, the access operation ends.

8.2.6 Data reporting requirements

When the reporting conditions set by the access report rule parameters are met, the read-write device will report the address parameters according to the (P_ReportDestination) requires that the data be uploaded to other devices or systems through the designated communication link.

8.2.7 Message content

8.2.7.1 Add access rule request message

The identifier is M_AddAccessSpec, add access rule request message, the content of the message body is shown in Table 15.

Table 15 The content of the request message body for adding an access rule

Serial number parameter identifier parameter data type parameter content

8.2.7.2 Add access rule response message

See Table 16 for the message body content of the Add Access Rule Response message.