Ebyte E840-DTU User Manual page 7

GPRS
USB to RS485 adaptor or USB to RS232 adaptor(optional)
1、 Enter the AT command mode and send +++ in the serial port assistant (+++ does not need to check to send a new line, other AT commands
need to tick to send a new line to be valid), one must send any other AT command within 3 seconds after sending +++
command for restarting) to enter the AT command mode completely.
2、 After entering the AT command mode, use AT+CPIN to check the SIM card access:
For example: AT+CPIN
+OK=1
For example ：AT+CPIN
+OK=1
Indicates that the SIM card is connected, and use AT+CSQ to view the current signal strength：
For example：AT+CSQ
+OK=26
Execute the parameter modification command. If the baud rate is modified, it needs to be restarted to be valid.
3、 Access server, AT + SOCK = TCPC, 116.62.42.192, 31687 parameters separated by English characters comma, IP instructions are separated by
English characters, after return + OK, one need to restart command AT + REBT to make it valid Here, the IP is only a demonstration, and the
actual connection is based on the IP of the server to be connected.
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
6
E840-DTU（GPRS-03）User Manual
GPRS sucker antenna
(except for AT