User's Manual

Document : WCAMODHEL.sxw
5.4.4 - Format of the commands – from the request transmitter side
➢ Broadcast requests – 0x28 ou 0x2A (REQ_SEND_BROADCAST or
REQ_SEND_BROADCAST_MESSAGE)
REQ_SEND_BROADCA ST ou REQ_SEND_BROADCAST_MES SAGE
HEADER CMD D ATA CRC ETX
3 bytes 1 byte 6 bytes variable 2 bytes 1 byte
0xFF ; 0x02 ;
0xXX
0x28
Group number to
interrogate in broadcast
mode
n bytes of data to transmit
the maximum size is 152
bytes
0x03
 Group number to interrogate : Only the most significant byte (MSByte) really corresponds to the
number of group, the 5 other bytes are not significant.
Remark : if the number of group is 0xFF 0xXX 0xXX 0xXX 0xXX 0xXX, all the modules receiving the
broadcast frame are authorized to transmit a response.
➢ Acknowledgement of the request – 0x21 (RES_SEND_FRAME)
RES_SEND_FRAME
HEADER CMD D ATA CRC ETX
3 bytes 1 byte 1 byte 2 bytes 1 byte
0xFF ; 0x02 ;
0x05
0x21
Status
0x00 : transmission OK
0x01 : transmission error
0x03
➢ Response to the broadcast request – 0x34 (RECEIVED_BROADCAST_RESPONSE)
RECEIVED_BROADCAST_RESPON SE
HEADER CMD D ATA CRC ETX
3 bytes 1 byte 1 byte 1 byte 1 byte 6 bytes variable 2 bytes 1 byte
0xFF ; 0x02 ;
0xXX
0x34 Status
Total
number of
frames
received
Frame
s
Index
Radio
address of
the
transmitter
of the
response
Received
data
152 bytes
max.
0x03
 Status : = 0 : reception Ok
= 1 : indicate that the number of received responses is higher than 255. in this case,
only the first 255 responses will be sent to the host.
 Frames index : This index is used by the wavecard to know how many responses must be sent
to the host. this index is decreased on low level acknowledgement, when the wavecard send a
response to its host.
The host knows that all the responses was sent to him, when the frames index indicates 1.
WCAMODHEL Handbook page 63 of 74