Страница 1 мировой engineering стандарты общая спецификация

8.3.8 Tester Implications. 
This service should only be physically addressed (point to point).
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GM WORLDWIDE ENGINEERING STANDARDS
GMW3110
8.4 ReadDataByIdentifier ($1A) Service. 
The purpose of this service is to provide the ability to read the
content of pre-defined ECU data referenced by a dataIdentifier (DID) which contains static information such as
ECU identification data or other information which does not require 
real-time 
updates. (
Real-time 
data is
intended to be retrieved via the ReadDataByPacketIdentifier ($AA) service.)
8.4.1 Service Description. 
The request message shall always include one dataIdentifier. The length of the
positive response message shall be adapted to the size of data referenced by the dataIdentifier parameter
value. This message shall include the dataIdentifier parameter value received in the request message.
The tester is only required to provide the dataIdentifier value desired. The target ECU is responsible for
knowing the address location and block length corresponding to the requested DID. An ECU is not required to
support all corporate defined DIDs, and may support additional application specific DIDs.
Note: 
Appendix C of this specification contains a list of corporate standard DIDs.
8.4.2 Request Message Definition (Table 68).
Table 68: ReadDataByIdentifier Request Message
Data Byte Parameter Name
Cvt Hex Value Mnemonic
#1
ReadDataByIdentifier Request Service Id
M
1A
SIDRQ
#2
dataIdentifier
M
xx
DID_
8.4.2.1 Request Message Sub-Function Parameter $Level (LEV_) Definition. 
This service does not use a
sub-function parameter.
8.4.2.2 Request Message Data Parameter Definition. 
Table 69 specifies the data parameter definitions for
this service.