Echelon FTXL - Manual (Page 93)

FTXL User’s Guide 81
process FTXL events. This function then calls event handler functions (such as
LonNvUpdateOccurred() or LonNvUpdateCompleted()).
The following sections describe the tasks that an FTXL application performs
during its life cycle.
Initializing the FTXL Device
Before your application initializes the FTXL LonTalk protocol stack, it must
initialize the C runtime environment and the operating system.
Your application must call the LonInit() function once during device startup. The
implementation of this function is generated by the LonTalk Interface Developer
utility, and is included in the FtxlDev.c file. This function initializes the FTXL
LonTalk API, the FTXL LonTalk protocol stack, and the FTXL Transceiver. The
main application thread must call this function before it calls any other FTXL
LonTalk API functions.
The LonInit() registers the FTXL device interface data with the FTXL LonTalk
protocol stack. This data defines the network parameters and device interface. If
your application needs to change the network parameters or change the device
interface, it can call the LonExit() function to shut down the FTXL LonTalk
protocol stack, and then call the LonInit() function to restart the protocol stack
with the updated interface.
Add a call the LonInit() function to the beginning of the application’s main
thread. If this function is successful, your application can begin normal
operations, including calling the event pump, as described in Periodically Calling
the Event Pump .
Example:
void myMainThread(void) {
LonApiError sts;
sts = LonInit();
if (sts == LonApiNoError) {
// begin normal operations
}
}
Periodically Calling the Event Pump
As described in Callbacks and Events on page 76, your FTXL application must
periodically call the LonEventPump() function to check if there are any
L
ON W ORKS events to process. This function calls specific API functions based on
the type of event, then calls event handler functions to notify the application
layer of these network events. You can call this function from the idle loop
within the main application thread or from any point in your application that is
processed periodically. However, you must call this function from the same
application context (task or thread) that called the the LonInit() function.
The FTXL LonTalk API calls the LonEventReady() callback handler function
whenever an event has been posted. This function is typically called from an
FTXL LonTalk protocol stack task or thread, and you must not call the
LonEventPump() function directly from the callback. However, your application
could define an operating system event which is signaled by the
LonEventReady() callback handler function. From within your application’s