Datasheet

Either connected device can initiate SDEP transactions, though certain transport protocols
imposes restrictions on who can initiate a transfer. The master device, for example, always
initiates transactions with Bluetooth Low Energy or USB, meaning that slave devices can only
reply to incoming commands.
Every device that receives a Command Message must reply with a Response Message , Error
Message or Alert message .
Message Types
Command Messages
Command messages (Message Type = 0x10) have the following structure:
Command ID (bytes 1-2) and Payload Length (byte 3) are mandatory in any command
message. The message payload is optional, and will be ignored if Payload Length is set to 0
bytes. When a message payload is present, it’s length can be anywhere from 1..16 bytes, to
stay within the 20-byte maximum message length.
A long command (>16 bytes payload) must be divided into multiple packets. To facilitate this,
the More data field (bit 7 of byte 3) is used to indicate whether additional packets are
available for the same command. The SDEP receiver must continue to reads packets until it
finds a packet with More data == 0, then assemble all sub-packets into one command if
necessary.
The contents of the payload are user defined, and can change from one command to
another.
A sample command message would be:
Name
Message Type
Command ID
Payload Length
Payload
Type
U8
U16
U8
...
Meaning
Always '0x10'
Unique Command Identifier
[7] More data
[6-5] Reserved
[4-0] Payload length (0..16)
Optional command payload (parameters, etc.)
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