USR-TCP232-T2 user manual
Jinan USR IOT Technology Limited
52
5.3.
AT comment
5.3.1. AT command overview
AT+ command is the command collection that perform the command transport using UART and module under the
order mode. Later we will interpret the type in detail.
Powered successfully, we can setting the module with UART.
The default UART port parameters of the module are: baud rate1152000, no parity, data 8 and stop 1.
Instr
AT command test tools. UART interface command to use secureCRT software tool or USR pro APP. Below are using the
secureCRT with UART to perform.
From transparent transport to AT command need two step as below:
Fill “+++”in the UART. After the module receive the “+++”,it will send a “a” to confirm;
Fill the confirming “a” in the UART, after the module receive and send “+ok”, enter the AT command mode.
Instr: if no feedback after fill “+++”and “a”, as the above.
Fill “+++”and “a” need to achieve in the time to reduce the chance of entering command mode while working
normally accidentally. Detail requirement are as fellows.
Diagram5.3.1-1 AT command time tree
Time requirement:
T1>the interval of serial port package
T2<300ms
T3<300ms
T5<3s
The order change into temporary command mode from transparent transport mode:
1. Serial mode device send “+++”to module continuously. The module receive and send “a” back. Before
s++”is the packaging time and can not send any data.
2. After receive “a” feedback a “a”in 3s.
3. After the module receive “a, send “ok”to the device, and enter “AT”command
4. After the device receive “+ok” and know the module enter the AT command mode, then send AT command.
The order change into transparent transport mode from AT command mode:
