Uart Frame Scheme; Uart Free-Frame; Uart Auto-Frame - Jinan USR IOT Technology USR-WIFI232-A2 User Manual

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According to the provisions of 802.11 protocol, different wireless networks can have a same

network name (i.e. SSID / ESSID), but must correspond to a unique BSSID address (i.e. MAC

address). Illegal intruders can create a wireless network with the same SSID / ESSID, it will make

STAs in the network to join to the illegal AP, thereby and then network leakage happen.

Users can prevent STA from joining to illegal network by binding the BSSID address, to improve

wireless network security.

4.6 UART Frame Scheme

USR-WIFI232-A2 support UART free-frame function. If user select open this function, module will

check the intervals between any two bytes when receiving UART data. If this interval time

exceeds defined value (50ms default), USR-WIFI232-A2 will think it as the end of one frame and

transfer this free-frame to WiFi port, or USR-WIFI232-A2 will receive UART data until 4K bytes,

then transfer 4KB frame to WiFi port.

USR-WIFI232-A2 is default interval time is 50ms. User can also set this interval to fast (10ms)

through AT command. But user have to consider if user MCU can send UART data with 10ms

interval ,or the UART data may be divide as fragment.

Through AT command: AT+FUARTTE=fast/normal, user can set the interval time: fast (10ms) and

normal (50ms). This command is factory default setting command and AT+RELD can't change its

value.

USR-WIFI232-A2 support UART auto-frame function. If user select open this function and setting

auto-frame trigger length and auto-frame trigger time parameters, then module will auto framing

the data which received from UART port and transmitting to the network as pre-defined data

structure.

Auto-frame trigger length: The fixed data length that module used to transmitting to the



network.

Auto-frame trigger time: After the trigger time, if UART port received data can't reach auto-



frame trigger length, then module will transmitting available data to the network and bypass

the auto-frame trigger length condition.

Detailed UART auto-frame function can refer to AT+ instruction set "UARTF/UARTFT/UARTFL"

introduction.

Jinan USR IOT Technology Limited

USR-WIFI232-A2 User Manual

Page 29 of 76

http://www.usriot.com

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