Technical Manual

Table Of Contents
60
Software
frames: normal (type 8), extended (type 37), and reduced (type 38); the A733 an-
swers with the extended type (see also “Data12” on page 62).
init_time represents the actual time to be used by the remote to re-initialize
its local RTC; if its value is time_t NULL (default), then no re-initialization will
be performed.
req_time is the time for requested data. An A733 will search its internal data
buffer for data that has a time stamp that is strictly newer than req_time.
Therefore, if a master requests data with exactly the time stamp previously
supplied by the remote, the remote must deliver a newer data slot. If the re-
quested data is too old, the remote will send its oldest data, while if the re-
quested data is too new, the remote will answer with the newest data it has.
If the device is not yet initialized and has no data (i.e. its internal time is 1/1/
1970), then it will send a Data12 frame with no relevant data, but with the time
stamp of 1/1/1970. This mechanism will inform a master that the device needs
initialization.
On the A733 this command can be initiated by means of the DATA command (see
also “DATA” on page 50).
SEE ALSO Data12 frame.
Broadcast Answer
ID 2
FORMAT struct {
unsigned char RF_levelOut;
} broadcast_answer;
DESCRIPTION
This is the answer to a broadcast request frame; the RF_levelOut is the level record-
ed by the device when receiving the broadcast request frame. The A733 will receive
and interpret such frames depending on the mode it was in when it issued the
broadcast request (see also “Broadcast Request” on page 60). In terminal mode, all
the broadcast answers will be displayed with their RF levels, while in connectivity
check mode, the LED tool will be activated. The device will pulse the LED tool for
the number of answers it identified.
If the A733 receives a Broadcast request, it must answer to it, but in a random man-
ner. An 8 seconds time interval starting with the end of the Broadcast request frame
is divided in 16 slots, each 0.5 seconds long. The A733 must select randomly one of
these 16 slots for sending its answer. This frame, as well as the Broadcast request
frame, is not routable.
SEE ALSO Broadcast Request frame.
Broadcast Request
ID 6
FORMAT The data frame body is empty.