User's Manual

Table Of Contents
USR-G809 User Manual Technical Support:
h.usriot.com
Jinan USR IOT Technology Limited www.pusr.com
98
T1 > current serial port packaging interval
T2 < current serial port packaging interval time
T3 < current serial port packaging interval time
T4 = current serial port packaging interval time
T5 < 3 s
T6 = current serial port packaging interval time
The time sequence of switching from transparent mode/HTTP mode to “AT Command mode” :
1. Serial device continuously sends "+++" to the device. After receiving "+++", the device will send an "a" to
the serial device. No data can be sent during a packaging cycle before sending "+++".
2. When the serial device receives “a”, a “a” must be sent to the device within 3 seconds.
3. After receiving 'a', the device returns "+ok" and enter “temporary command mode”.
4. After receiving "+ok", the device has enter "temporary command mode" and now can send AT command
to it.
Time sequence of switching from AT command mode to transparent mode.HTTP mode:
1. Serial device sends "AT+ENTM" to G809.
2. After receiving the command, sends "OK" to the serial device and returns to the previous working mode.
3. After the serial device receives "OK", it knows that the device has returned to its previous working mode.
10.2. Serial AT Commands
In transparent mode, do not need to switch to the command mode, we can use “Command password + AT
command” to query and set parameters. It does not need complicated “+++” timing sequence to enter AT
command mode, so as to quickly query or set parameters.
Before sending, enter AT command mode, query the command password firstly. It defaults to “test.cn#”.
Restart the device after setting.
Send “test.cn#AT+MAC” from the serial port (there is an “Enter” after the command), then can receive the
response from the device: