Iso15675 Road Vehicle Control Local Area Network diagnosis part 2 network layer service Reading Notes (1)

Reference books: Chinese version of the iso15675 protocol.

Control Local Network diagnosis

Part 2: Network Layer services

1. Communication Service

N_usdata.request

Used by the upper layer of the sender to transmit control information and diagnostic service data to the network layer.

N_usdata.ffindication description of the first frame of the data transmission service

Description of the beginning of the information passed to the upper layer

N_usdata.indication description

Used by the network layer of the acceptor to indicate the execution results of data reception at the upper layer.

N_uadata.confirm validation service

Used by the sender's network layer to confirm the execution results of required services at the upper layer

2. Protocol Parameter definition Service

N_changeparameter.request network layer parameter change service requirements

N_changeparameter.confirm network layer Change parameter service confirmation

3. operations at the network layer

Single-frame message transmission (upper half)

Multi-frame message transmission (lower half)

The Flow Control Frame notifies the sender of the network layer capacity of the receiver to notify the sender of the next data size.

Some acronyms are attached:

Mtype Message Type

N-AE network address extensions

N-AI address information

N-AR network layer timing parameter ar Receiver

N-AS network layer timing parameter as sender

N-BR network layer timing parameter BR until receiving next flow control time

N-BS network layer timing parameters BS until the next flow control is transferred

N-changeparameter network layer service name

N-CR network layer timing parameter Cr until receiving next Continuous Frame Time

N-CS network layer Timing Parameters Cs until the next continuous frame is transferred

N-Data Network Data

N-PCI Network Protocol control information

N-pcitype Network Protocol control information type

N-PDU Network Data Control Unit

N-SA network resource address

N-SDU Network Service Data Unit

N-TA network Destination Address

N-tatype network Destination Address type

N-usdata network layer unrecognized split data transmission service name

Nwl Network Layer

Original request service requirements

R Receiver

S Transmitter

SF single framework

Data Length of SF-DL Single Frame

Sn

Stmin minimum wait time between two data packets

BS block size

Cf Coherent Structure

Confirm confirmation

ECU Electronic Control Unit

FC Flow Control

FF framework 1

Data Length of FF-DL first frame

FS flow status

Indication instructions

1. Network Layer services

The general structure of all network-layer services is the same as follows:

Sevice_name.type {

Parameter;

Parameter B;

Patameter C:

......

}

"Sevice_name" is the service name, for example, n_usdata, "type" indicates the service primitive type "parameter A, B, C" is a series of values transmitted by the n_sdu service primitive.

"Sevice primitives" defines how service users (such as diagnostic applications) work with service providers (such as the network layer.

1) n_usdata.request

The <message data> and <length> information of the recipient defined in the address information are transmitted through the request service primitive. The upper layer of the sender is sent to the sender's network layer.

N-USData.request {

Mtype Message Type

N-SA network resource address

N-TA network Destination Address

N-tatype network Destination Address type

N-AE network address extensions

<Messagedata>

<Length>

}

 

Every time the n_usdata.request service is called, the network layer sends a signal indicating whether the message transmitted to the service user is successful. This signal is used to call the n_usdata.confirm service.

2) N-USData.confirm

The service has been issued by the network layer. This service primitive is used to confirm whether the n_usdata.request Service identified in the address information is complete. The <n_result> parameter provides the request service status.

N-USData.confirm {

Mtype

N-SA network resource address

N-TA network Destination Address

N-tatype network Destination Address type

N-AE network address extensions

<N-result>

}

3) n_usdata_ff.indication

The service is sent by the network layer. The service primitive indicates to the adjacent upper layer that it has received the first frame of the segment message from the same protocol entity.

N-USData.FFindication {

Mtype

N-SA network resource address

N-TA network Destination Address

N-tatype network Destination Address type

N-AE network address extensions

<Length>

}

This service is followed by an n_usdata.indication service from the network layer to indicate whether the message is successfully received.

Note: The network layer calls this service only when a correct first frame and packet segment are received. If the network layer detects any errors of the first frame, this packet will be ignored by the network layer, nor will n_usdata_ff.indication be sent to the adjacent upper layer. If the network layer receives the first frame, its first frame data length (ff_dl) is greater than the maximum Buffer Capacity of the receiver. This is also considered an error and n_usdata_ffindication will not be sent to the upper layer.

4) n_usdata.indication

Issued by the network layer. This service primitive indicates the <n-result> event and transmits <length> <messagedata> bytes. The information comes from the equivalent protocol entity indicated in the address information, and send it to the adjacent upper layer.

N-USData.indication {

Mtype

N-SA network resource address

N-TA network Destination Address

N-tatype network Destination Address type

N-AE network address extensions

<Messagedata>

<Length>

<N-result>

}

Where <n-result> is a N-OK, <length> <messagedata> is valid.

Note: this service call marks the completion of receiving a single frame message or a segmented message. If the network layer detects any errors in a single frame, the packet will be ignored by the network layer and the service will not be sent to the upper layer.

5) n_changeparameters.request

The Network Layer requests to change the parameters. It is acceptable to change the parameters, but it is not allowed after the first frame n_usdata_ff.indication is received and before the communication packet (n_usdata_indication) is received.

N-Changeparameter.request {

Mtype

N-SA network resource address

N-TA network Destination Address

N-tatype network Destination Address type

N-AE network address extensions

<Parameter>

<Parameter-value>

}

6) n_changepatameters.confirm

N-Changeparameter.confirm {

Mtype

N-SA network resource address

N-TA network Destination Address

N-tatype network Destination Address type

N-AE network address extensions

<Parameter>

<Result-changeparameter>

}

Not complete to be continued ~~