GPRS event reporting

5 thoughts on “GPRS event reporting

  1. Hello all!

     

    I have a question about the event reporting for the use with an GE-864 QUAD V2. As i’m currently working on the software design for a new project, i’ve got only the documetation to go on.

     

    My question is as follows:

     

    How are errors handled while the module is in gprs data-mode? If the connection gets (improperly) terminated for example, will the unit exit data-mode by itself and report the events or will it wait on the global time-out to exit data-mode?

     

    Error handling whas’nt really clear to me while I read though the documentation. 

    1. A proper close of a connection by both parties is signaled with "NO CARRIER" and return to command mode, however there are cases when connections are "stale" because of improper disconnects or failures in the network chain, the module not being aware of the situation. To overcome as much as possible these situations there is a socket timeout value to be set at a convenient value, a native socket keep alive feature and one can implement his own timeouts and keep alive mechanism in his software and communication protocol to be 100% secure.

       

       

  2. Thank you for your fast answer!

     

    I think I get it, but one question remains however:

     

    How do you differentiate between data-mode and command-mode, if the application thinks the module is in data-mode?

     

    Do I always have to look for the "NO CARRIER" signal or does the module otherwise signal the controlling application that it has come out of data-mode?

     

    1. In command mode the module answers to AT commands Smile … and DCD signal can be used to detect the state. Of course response codes such as CONNECT, NO CARRIER can be used to keep track of modem state.