0x22, 0x2e services of UDS

0x22 Service for reading did, The client request format is "22+did", The server must respond as “62+did+ data ”, The negative response is “7f+22+NRC code ”

for example ,F186 This did, Used to read the current session state of the server , The server has three states , Respectively 01、02、03

When the client sends 22+F186 The request is , The server will definitely return to the current session state ,

reply “62+F186+（01 or 02 or 03）”

as follows , The client sends 22f186, Server reply 62f18602 Indicates that the current session state is programming session .

Take a look at the DID Write data ：2E service . His request format “2E+2 Bytes of DID+ The value to be written ”; The format of the positive response “6E + DID”. Here is an example , from F1 90 To write VIN code , Write a 17 Bytes of VIN code , Simplify it here , Just make an ellipsis . When the write is successful ,ECU Reply positively “6E +F1 90”