USR-DR404 user manual
Jinan USR IOT Technology Limited
29
3.6. USR-Link
When works in AP mode, DR404 will open a UDP port which number is 49000 to receive the USR-link. Connected
directly to the WIFI of the DR404, phone query the SSID and set the router’s SSID and password via the command under the
UDP. Then the DR404 will restart automatically and connect the router, now it works in STA mode.
Protocol format description:
Name
Bytes
Description
1
Packet
Header
1
Fixed value: 0xFF
2
Length
2
Number of all bytes after length (excluding length) and before
parity (excluding parity)
3
Command
1
Command type, 0x01 is the query command
4
Parity
1
The accumulated sum of all bytes after the header (excluding
the header) and before the parity (excluding the parity).
Form 9 Query Command
Name
Bytes
Description
1
Packet
Header
1
Fixed value: 0xFF
2
Length
2
Number of all bytes after length (excluding length) and before
parity (excluding parity)
3
Command
1
Command type, the reply command corresponding to the query
command is 0x81
4
Number of
APs
1
Number of APs searched
5
SSID1
Indefinite
length
SSID of route 1
6
Terminator
1
Terminator for SSID of Router 1, fixed value is 0x00.
7
Signal
strength1
1
The signal strength of router 1 network, ranges from 0 to 100, and
the corresponding actual value is 0% to 100%.
8
Terminator
2
Terminator for signal strength 1, 0x0D, 0x0A
。
…
…
…
………
M
SSIDn
Indefinite
length
SSID of route n
M+1
Terminator
1
Terminator for SSID of Router n, fixed value is 0x00.
M+2
Signal
strength n
1
The signal strength of router n network, ranges from 0 to 100, and
the corresponding actual value is 0% to 100%.
M+3
Terminator
2
Terminator for signal strength n, 0x0D, 0x0A
。
M+4
Parity
1
The accumulated sum of all bytes after the header (excluding the
header) and before the parity (excluding the parity).
Form 10 Reply Command