Document : CS-SUP-MUTI-WPORTAPP-E02.sxw
5.4- ’Broadcast’ mode
This mode allows to address a request to all the equipments in radio range of the transmitter. Thus, it is not
necessary to specify the address of the distant equipment to reach.
Depending on the command used, the request can be sent with, or without awaiting for a response
( REQ_SEND_BROADCAST, or REQ_SEND_BROADCAST_MESSAGE commands).
In all cases, two types of exchanges in broacast mode can be distinguished,
Not-selective Broadcast :
all the distant equipments in radio range of the transmitter, are
interrogated.
Selective Broadcast
: only a given group of distant equipments in radio range of the transmitter,
are interrogated.
5.4.1 - Configuration of the parameters relating to the 'Broadcast' mode
The parameters are accessible by commands
REQ_READ_RADIO_PARAM
, and
REQ_WRITE_RADIO_PARAM
(all
the parameters are developed in appendix 3).
NUM
DESCRIPTION
VALUE
SIZE
(in
bytes)
0x0E
EXCHANGE_STATUS
: parameter relative to
the error or status frame management activation
(see chapter , , et 5.4).
0 : status and error frame deactivated,
1 : error frame activated,
2 : status frame activated,
3 : both status and error frames activated,
by default, RECEPT_ERROR_STATUS = 0x00.
1
0x17
BCST_RECEPTION_TIMEOUT : timeout used
for the reception of CSMA frame consecutively
to REQ_SEND_BROADCAST Command
emission (available from firmware V2.01
version )
Valeur in multiples of100ms.
Default = 0x3C (6 seconds)
1
5.4.2 - 'BroadCast' mode without waiting for a response
This mode allows to address a request to all the equipments in radio range of the transmitter, without waiting
for a response. Depending to the setting of the EXCHANGE_STATUS parameter, the Wavecard will be
available for next RS232 serial link exchange :
After transmitting the broadcast request,
On reception of the END_MESSAGE_EXCHANGE command.
a) Description of the commands
CMD
NAME
DESCRIPTION
0x21
RES_SEND_FRAME
Response from the radio board to the frame emission (response to
the request 0x20, 0x22,0x24, 0x26, 0x28, 0x2A )
0x2A
REQ_SEND_BROADCAST_MESSAGE
Request to send a radio frame in broadcast mode without
waiting for radio response.
0x37
END_MESSAGE_EXCHANGE
Frame indicating end of message exchange.This frame is
returned only after
0x22
&
0x24 & 0x2A
Request command.
Reception of this frame is conditioned by the parameter
EXCHANGE_STATUS value.
0x38
RECEIVED_BROADCAST_FRAME
Received a radio frame transmitted in a broadcast mode
WaveCard user handbook
page 56 of 67
