ReadDataByIdentifier (0x22) service

Service description

The ReadDataByIdentifier service allows the client to request data record values from the server identified by one or more dataIdentifiers.

The client request message contains one or more two byte dataIdentifier values that identify data record(s) maintained by the server. The format and definition of the dataRecord shall be vehicle manufacturer or system supplier specific, and may include analog input  and output signals, digital input and output signals, internal data, and system status information if supported by the server.

The server may limit the number of dataIdentifiers that can be simultaneously requested as agreed upon by the vehicle manufacturer and system supplier.

Upon receiving a ReadDataByIdentifier request, the server shall access the data elements of the records specified by the dataIdentifier parameter(s) and transmit their value in one single ReadDataByIdentifier positive response containing the associated dataRecord parameter(s). The request message may contain the same dataIdentifier multiple times. The server shall treat each dataIdentifier as a separate parameter and respond with data for each dataIdentifier as often as requested.