Technical data

Special case: requesting data (service: SRD with 0 bytes of data to be
transmitted)
Sequence of the transmission
If the sender does not have data to transmit to the receiver, but only wants
to request data from the receiver, use the SRD service with 0 bytes of data
to send. The terms "sender" and "receiver" are retained even if the "sender"
has no data to transmit, but only requests data.
The "receiver" transfers the requested data to the buffer using the "reply
update single (RPL_UPD_S)" service or the "reply update multiple
(RPL_UPD_M)" service. How the data are transferred to the buffer and
handled in the buffer has already been described above. The sequence is
illustrated schematically in Figs. 8.10 and 8.11 with the special feature that
in Fig. 8.11 there are no data to be transmitted with the SRD request (data
1 = 0).
B8976060/02 Free Layer 2 Communication
8 - 27 Volume 1