Echelon FTXL User Manual

Page 96

Advertising
background image

84

Developing an FTXL Application

application-specific processing of update completion. Figure 10 shows the control

flow for processing a network variable update.

LonPropagateNv()

FTXL Application

FTXL LonTalk Protocol

Stack and API

Send Network Variable

Update to Network

Add “Update Complete”

Event to Queue

LonEventPump()

LonNvUpdateCompleted()

LonEventReady()

Figure 10. Control Flow for Sending a Network Variable Update to the Network

In the case of an unacknowledged or repeated service type, the FTXL LonTalk
protocol stack considers the update complete when it has finished sending the

update to the network. In the case of an acknowledged service type, the FTXL
LonTalk protocol stack considers the update complete when it receives

acknowledgements from all receiving devices, or when the retry timer expires

n

times (where

n

is the retry count for the network variable + 1).

To process an update failure, edit the LonNvUpdateCompleted() callback handler

function in the FtxlHandlers.c file. This function is passed the network variable

index (the same one that you passed to the LonPropagateNv() function), and is
also passed a success flag. The function is initially empty, but you can edit it to

add your application-specific processing. The function initially appears as:

void LonNvUpdateCompleted(const unsigned index, const

LonBool

success)

{

/* TBD */

}

Advertising