What is the meaning of the error “ER_NOTREADY – Function called when service not available”?
This error arises in two common circumstances, usually when using functions to communicate with the Application or Physical layers: • When a node is rebooting (its EV_REBOOT event handler is executing) data frames may not be written to the Physical Layer – it too needs to be rebooted before it can accept data. To overcome this limitation, set a timer for a very short interval, say just 1usec, and write to the Physical Layer in the timer’s handler. • cnet employs an event-driven paradigm to inform your protocol code that the Application and Physical layers require your attention. You may not poll either layer to see if new messages or data frames are available. Attempts to call CNET_read_application when not executing an EV_APPLICATIONREADY handler, or attempts to call CNET_read_physical when not executing an EV_PHYSICALREADY handler, will result in the functions failing and setting cnet_errno to ER_NOTREADY.
