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Copyright © 2008 Somfy SAS. All rights reserved - V0 - 09/2008
Message Format
Byte Number
Name
Value
Description
1
MSG
See Message
Table
Refer to ‘MSG’
column in the table below for a list of
available messages.
2
LEN
3
Reserved
04h
Refer to ‘LEN’
column to have the correct value
depending on message.
4 - 6
SRC@ (*) (**)
Node dependant
(refer to product label)
Always 04h for RS485 4IL
T interface
7 -9
DEST@ (**)
...
DA
TA
See Message
Table
Information on DA
TA
fields can be found below :
- Length of DA
TA
part (in byte count)
- T
ype of every DA
TA
fields
- A
vailable values for each DA
TA
fields
Byte n-1
CHECKSUM
Byte 1 + … + Byte (n-2)
CHECKSUM is one’
s complement of sum of bytes 0 to
byte (n-2) If CHECKSUM not correct, message is ignored.
Byte n
NodeID of the transmitter (SouRCe address)
NodeID of the receiver (DEST
ination address)
(*) When the host is not a SOMFY
product, its source address shall be included in the following values : FF FF 00 <= SCR@ <= FF FF FE
(**)
Address values are LSBF
.