store commands in database

Why not store commands in a table while sending and update the record while device return some data.

For example, GT06 return a error messagem engine stop command and the car is more then 20km/h.

Why not log this returns?

Good point. I'll consider storing commands in the database.

For example,

This time I sent a command to stop engine, and the command not worked, I will see the logs and I get this HEX: 787818151000000000496e76616c6964204669782100020077a57b0d0a

decoding msg: " Invalid Fix! "

so, I think is better you create a command table and make this log.

In most of protocols, commands can go with a ID of the commmand, when the device return the command status come with the passed ID

Thanks for the information.