Auto-Diag-16: Read Data by Periodic Identifier — All Auto Tech

READ DATA BY PERIODIC IDENTIFIER

The Read data by Periodic Identifier service allows the client to request the server/ECU to periodically transmit the response for one or more identifiers

The service ID for the Read data by periodic Identifier is 0x2A

Important points about the service

• The periodic identifier response transmission mode would be set per a request message. If it has to be changed, another request message has to be sent to the server/ECU
• The server/ECU will transmit a positive response with the data identifier only for the request message and then start the timer for the periodic transmission of data
• The periodic positive response message will contain the data identifier followed by the data parameters of the identifier
• To stop the service, a request message has to be sent by the client with the transmission mode as “Stop”. We will see more about this in the coming sections
• Based on the design requirements by the vehicle manufacturer, the ECU may limit the number of identifiers that can be simultaneously supported. If the request exceeds the number of supported simultaneous identifiers, the ECU can respond with a negative response and none of the periodic identifiers may be scheduled.

Transmission modes supported are Message flow examples