void ar_get_latest (short board, short channel, unsigned short label, void * data, char * seq_num);
This function retrieves the latest ARINC 429 message received for the specified channel/label combination from the snapshot buffer.
When using this function, the host application should set the snapshot storage mode to label field only, (see the documentation on the function ar_set_device_config, for the configuration option ARU_ACCESS_SNAPSHOT_BUFFER). This will setup the device to store snapshot data based on the label field value only, ignoring the SDI bit field value.
If the label parameter value requested is either 256 or the value ARU_ALL_LABELS (511), this function treats the data parameter as an array reference and returns the most recent received ARINC 429 message for all 256 valid ARINC labels for the specified channel, in successive data array elements. This function assumes that the caller has allocated at least 1024 bytes for data when used in this mode.
If no message has been received for the specified channel/label since the last initialization of the device, a data value of zero will be returned.
Input |
||
Name |
Type |
Description |
board |
short |
(input) Device Number of the board to reference, (valid range is 0-15). |
channel |
short |
(input) Specifies which receive channel this routine is to access. Valid range is 0 to one less than the installed ARINC 429 receive channel count. |
label |
unsigned short |
(input) The 8-bit label value of interest. |
Output |
|
|
Name |
Type |
Description |
data |
any type (passed by reference) |
(output) The latest received 32-bit ARINC 429 message value for the specified label. |
seq_num |
char (passed by reference) |
Unsupported legacy parameter, not used or set. Present for cross-API compatibility only. |
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