ZAURA Datasheet, PDF (23/99 Pages) –

ZAURA RF Wireless Library
Programmer’s Reference Manual
11
Reliable Data Transfer & Flow Control Protocol
When the ZAURA RF Wireless Library is configured to use the
DA_SA_CTRL frame format, the application can choose to send unicast
frames unreliably or reliably via the Reliable Data Transfer & Flow Con-
trol (RDTFC) protocol. Broadcast frames cannot be transmitted using
RDTFC and will be sent unreliably even if the application requests reli-
able delivery.
The wireless reliable data transfer protocol cannot guarantee that a trans-
mitted packet will be received by the target (e.g., the target is out of radio
range). In some cases it is not even possible for the transmitter to deter-
mine that a target successfully received a frame (e.g., ACK lost). Even
with these limitations, the RDTFC protocol ensures that the receiver will
not accept duplicate frames. If the RDTFC indicates that a reliable data
transfer succeeded, it guarantees the target actually received the frame.
Service Access Points
When the ZAURA RF Library is configured to use the DA_SA_CTRL
frame format, the least significant four bits of the control field of DATA
and SDATA frames identify the target Service Access Point (SAP). A Ser-
vice Access Point is a process that expects data in a certain format and
performs a specific function on that data. Of the 16 possible SAP values,
4 are reserved for the use of the ZAURA RF Library and the remaining 12
can be arbitrarily defined by the user’s application.
Table 3. Service Access Point Labels and Functions
SAP
0–11
12
13
Label
SAP_APP_0 to SAP_APP_11
SAP_RESERVED_12
SAP_RESERVED_13
Function
Defined by the application.
Reserved.
Reserved.
RM006003-1011
Reliable Data Transfer & Flow Control