USR IOT USR-G771-E User manual

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USR-G771-E User Manual
Document version: V1.0.5

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1. Introduction ............................................................................................................................................................. 3
1.1. Overview ...................................................................................................................................................... 3
1.2. Features ....................................................................................................................................................... 3
2. Get Started ..............................................................................................................................................................4
2.1. Specification ................................................................................................................................................. 4
2.2. Hardware ......................................................................................................................................................5
2.2.1. Dimensions ........................................................................................................................................5
2.2.2. Indicators ........................................................................................................................................... 6
2.2.3. Connecting Hardware ........................................................................................................................6
3. Utility Configuration .................................................................................................................................................7
3.1. Download the Utility ..................................................................................................................................... 7
3.2. Starting the Configuration Utility .................................................................................................................. 7
4. Serial Port ............................................................................................................................................................... 9
4.1. Basic Parameters .........................................................................................................................................9
4.2. Frame forming mechanism ........................................................................................................................ 10
4.2.1. Time Trigger .................................................................................................................................... 10
4.2.2. Length trigger .................................................................................................................................. 10
5. Selecting an Operating Mode ............................................................................................................................... 11
5.1. Transparent Mode ......................................................................................................................................11
5.2. HTTPD Client Mode ................................................................................................................................... 14
5.3. SMS Mode ..................................................................................................................................................16
5.4. MQTT Mode ............................................................................................................................................... 18
5.4.1. Generic MQTT .................................................................................................................................19
5.4.2. Subscribe/Public Topics .................................................................................................................. 21
5.4.3. AWS IoT Service ............................................................................................................................. 22
6. General Function .................................................................................................................................................. 31
6.1. Identity Package .........................................................................................................................................31
6.2. Heartbeat Package .................................................................................................................................... 33
6.3. Socket Distribution Protocol .......................................................................................................................34
6.4. Backup Socket ........................................................................................................................................... 35
6.5. SSL/TLS Encryption ...................................................................................................................................36
6.6. Security ...................................................................................................................................................... 37
6.7. NTP ............................................................................................................................................................ 39
6.8. FTP Upgrade ..............................................................................................................................................40
6.9. Base Station Geolocation ...........................................................................................................................40
6.10. Firmware Upgrade ................................................................................................................................... 40
6.11. Restore to Factory Default Settings .........................................................................................................41
6.12. Timeout Restart ........................................................................................................................................42
7. AT Commands ......................................................................................................................................................42
7.1. AT Command Settings ...............................................................................................................................42
7.2. Serial AT Commands ................................................................................................................................. 43
7.3. Network AT Commands ............................................................................................................................. 43
7.4. SMS AT Commands .................................................................................................................................. 44

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1. Introduction
1.1. Overview
USR-G771-E is a LTE CAT 1 communication modem, which supports LTE and GSM, covers the mainstream
frequency bands of European operators. It has perfect software function, supports TCP/UDP transparent
transmission, SMS transmission, HTTPD Client mode and AT command configuration. In addition, it is simple
to configure, has high reliability and built-in hardware watchdog, supports FOTA upgrading.
USR-G771-E supplies a wide voltage range power through terminal and DC interface, RS232 and RS485
standard interfaces, meets the needs of different application scenarios.
1.2. Features
Equipped with CAT-1 network, 10Mbps download rate, 5Mbps upload rate, meeting 80% of the data
transmission application scenarios
Low latency in milliseconds
Multiple modes, supports LTE CAT 1 and GPRS
Wide coverage, high stability based on existing 4G network
Supports TCP/UDP, HTTPD and SMS transparent transmission
Each socket supports buffering 20 packets of serial port data, each packet is up to 4K
Supports parameter configuration via network, serial and SMS AT command
Supports base station geolocation and NTP function
Support 9~36V wide voltage supply

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Multiple indicator lights, convenient and accurate to check the device status
Industrial grade, hardware watchdog, high reliability
2. Get Started
2.1. Specification
Parameters
Description
Basic Parameters
USR-G771-E
Supports B1/B3/B7/B8/B20
Power
DC 9V~36V
Operating current
Average: 21mA-50mA, maximum: 54mA (12V)
Indicators
POWER: Power indicator, always on after normal power supply.
WORK: Working status indicator, flashes every second.
NET: Network status indicator, green means 4G, red means 2G.
LINK: Socket A connection status indicator, always on after connecting.
DATA: Data transmission indicator, on when there is data transmission.
SIM/USIM
3V/1.8V SIM slot, 2FF
USB interface
Slave, MicroUSB, USB 2.0 High speed
UART interface
RS232 and RS485, baud rate 1200~230400 bps.
Antenna interface
SMA female cellular antenna connector
Environmental
Dimensions(mm)
82.6 × 86 × 25
Weight(g)
<110g
Temperature
Operating temperature
-30℃~ +75℃
Storage temperature
-40℃~ +90℃
Humidity
Operating humidity
5%~95% (non-condensing)
Transmission
speed
LTE FDD Rel.13
10MbpsDL/5Mbps UL
GPRS
85.6KbpsDL/85.6Kbps UL(multi-slot class 12)
Bands
LTE FDD
B1/B3/B7/B8/B20
GSM
900/1800MHz
TX Power
FDD:B1/3/7/8/20/28
23dBm±2dB
GSM:900MHz
33dBm±2dB
GSM:1800MHz
30dBm±2dB
Rx Sensitivity
GSM:900MHz
-109.5dBm
GSM:1800MHz
-108dBm
FDD:B1/3/20
-98dBm
FDD:B7
-97.5dBm
FDD:B8/B28
-98.5dBm

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Software
Operating mode
TCP/UDP/HTTPD/SMS transparent transmission, CMD mode
Configuration command
AT+command
Network protocol
TCP/UDP/DNS/FTP/HTTP/IPV4/IPV6
Socket number
4
User configuration
Serial/Network/SMS AT command
Features
Socket distribution protocol
Support
Heartbeat package
Support ICCID/IMEI/SN/User-defined/LBS
Identity package
Support ICCID/IMEI/SN/User-defined/CLOUD
FOTA self upgrade
Support
Backup socket
Support
Base station geolocation
Support
FTP upgrade
Support
NTP
Support
2.2. Hardware
2.2.1.Dimensions

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2.2.2.Indicators
There are five indicators on USR-G771-E, PWR, WORK, NET, LINKA, DATA.
Indicator
Function
Status
POWER
Power indicator
Always on after normal power
supply.
WORK
Working status indicator.
Flashes every second.
NET
Network status indicator
Green means 4G network, red
means 2G network.
LINKA
Socket A connection status indicator
Always on after socket A is
connected
DATA
Data transmission indicator
On when there is data
transmission
2.2.3.Connecting Hardware
If you have purchased, there will be the following accessories:
USR-G771-E
Antenna
Power adapter
Female to female
adaptor
Required additional equipment:
RS232 serial to USB cable

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PC
1. Installing SIM card and antenna：
Press the yellow button and the SIM card slot will pop up. Then Install the antenna.
2. Serial Connecting:
RS232: Using the standard RS232 to USB cable, connect the RS232 male connector into the RS232 port
on the G771-E. Connect the USB connector (other end of the cable) into the PC.
RS485: Connect pin A of the RS485 interface of the G771-E to pin A of the RS485 to USB adaptor, pin B of
G771-E to pin B of the adaptor.
3. Power Supply:
Connect 9-36V DC power adapter to power G771-E. Then “POWER” indicator will always on and the
“WORK” indicator will flash.
3. Utility Configuration
3.1. Download the Utility
Please download the utility in this link:
https://www.pusr.com/products/RS232/RS485-serial-to-Cat-1-771.html
3.2. Starting the Configuration Utility
USR-G771-E utility is shown as following:

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Description:
1. In PC serial parameter setting area, it is necessary to set the serial parameters consistent with the serial
device, otherwise they cannot communicate with each other.
2. Working mode selection area, select the work mode of the modem.
3. In the parameter setting area of characteristic functions, set parameters related to modem's featured
functions.
4. Modem parameter area, setup some basic global parameters.
5. Common command button, click to send the self-input command.
6. Data receiving and display area, displaying the data sent and received.
7. Data sending area, input the data and click Send.

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4. Serial Port
4.1. Basic Parameters
Serial parameters of USR-G771-E must be consistent with the parameters of the serial device. Serial port
parameters include basic parameters and framing parameters.
Item
Parameter
Baud rate
1200~230400bps
Data bit
8
Stop bit
1,2
Check bit
NONE
EVEN
ODD

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4.2. Frame forming mechanism
4.2.1.Time Trigger
When G771-E receives data from the UART, it continuously checks the interval of two adjacent bytes. If the
interval time is greater or equal to a certain "time threshold", then a frame is considered finished, otherwise
the data is received until greater or equal to the packet length byte set. This frame is sent to the network as a
TCP or UDP packet. The "time threshold" here is the time between packages. The range of settable is
10ms~500ms. Factory default: 50ms.
This parameter can be set by AT command, AT+UARTFT=<time>.
Note: T is the packing interval time.
4.2.2.Length trigger
When G771-E receives data from the UART, it constantly checks the number of bytes received. If the number
of bytes received is equal to a certain "length threshold", a frame is considered to have ended, otherwise the
packaging time is waiting for the end. This frame is sent to the network as a TCP or UDP packet. The "length
threshold" here is the package length. The settable range is 5~4096. Factory defaults to 1024.
This parameter can be set by AT command, AT+UARTFL=<length>.
Note: L is the packaging length.

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5. Selecting an Operating Mode
USR-G771-E has three operating modes: transparent mode, HTTPD Client mode and SMS mode.
5.1. Transparent Mode
In this mode, users do not need to pay attention to the data conversion process, can realize the bidirectional
data transparent transmission between serial devices and network servers.
G771-E supports 4 socket connections, Socket A, Socket B, socket C and socket D, which are independent with
each other. Each socket supports TCP Client and UDP Client.
Set parameters by the utility:

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Set by AT command:
Command
Operation
1
+++a
Enter serial AT command mode
2
AT+WKMOD=NET
Set the work mode to Transparent mode
3
AT+SOCKAEN=ON
Enable Socket A
4
AT+SOCKASL=LONG
Set Socket A to persistent link
5
AT+SOCKA=TCP,test.usr.cn,2317
Set the remote IP and port of Socket A
6
AT+S
Save all parameters and restart
Test
Connect the serial port of USR-G771-E to the computer via a RS232 serial to USB cable, send data from the
utility, the test server will return the same data to serial port.

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5.2. HTTPD Client Mode
In this mode, user’s terminal device can send request data to the specified HTTP server through this modem,
then the modem receives data from HTTP server, parses and sends data to the serial device.
User does not need to pay attention to the data conversion process between the serial data and the network
data packet, and can achieve the data request from the serial device to the HTTP server through simple
parameter settings.
The modem will filter out the received HTTP protocol header data by default, only output user data to the
serial port. Users can choose whether to filter by AT command.
Set parameters by the utility:

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Set by AT command:
Command
Operation
1
+++a
Enter serial AT command mode
2
AT+WKMOD=HTTPD
Set the work mode to HTTPD Client
3
AT+HTPTP=GET
Set the HTTP request type to GET
4
AT+HTPURL=/1.php?
Set the HTTP URL
5
AT+HTPSV=test.usr.cn,80
Set the HTTP server address and port
6
AT+HTPHD=Accept:text/html[0D][0A]
Set the HTTP request header
7
AT+HTPTO=10
Set the time of transitory link
8
AT+HTPPK=ON
Set whether to filter HTTP header
9
AT+S
Save parameters and restart the modem
Test
After the NET light is on, send the data in the format of "data =". After the data is sent successfully, server will
return the data.

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5.3. SMS Mode
In this mode, user's serial device can send SMS to the specified mobile phone and receive SMS from any
mobile phone. User can decide whether to transmit the data of the specified mobile phone to the serial
device through settings.
Users can send and receive SMS to check the serial device status remotely via G771-E.

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Set by the utility:
Set by AT command:
Command
Operation
1
+++a
Enter serial AT command mode
2
AT+WKMOD=SMS
Set the work mode to SMS
3
AT+DSTNUM=10086
Set the destination phone number
4
AT+SMSFLT=ON
Enable only receive SMS from source
number
5
AT+VOLTEEN=ON
Enable VOLTE function
6
AT+S
Save the parameters and restart
Note:
1. You need to add the international number before the destination phone number.
2. When only receive SMS from source number is enabled, other phone numbers can still query or set parameters.
Test
When the NET light is on, we can send and receive data in both directions via SMS with destination phone
number.

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5.4. MQTT Mode
Note: This function is only supported by firmware version 1.3.25 and above.

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In this mode, USR-G771 works as an MQTT Client, which can help users quickly access the built private MQTT
server or public MQTT IoT cloud platform. Users do not need to pay attention to the data conversion process
between serial port data and network data packets, and can realize data transparent transmission between
serial port and server only through simple parameter settings.
USR-G771 supports quick access to general MQTT server and Alibaba Cloud, and supports multi-topic data
publishing and data subscription.
Setup software is like below:
5.4.1.Generic MQTT
USR-G771 supports connection to standard MQTT protocol IoT platforms, such as Baidu Cloud, Tencent
Cloud, Huawei Cloud, AWS Cloud, etc., and supports reconnection interval configuration to adapt to different
MQTT servers. Support SSL/TLS encryption, and the authentication mode can choose not to verify the
certificate, one-way authentication certificate and two-way authentication certificate.

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Options
Descriptions
Default
MQTT Mode
Whether to enable MQTT mode
OFF
MQTT Version
V3.1, V3.1.1
V3.1.1
MQTT Server IP
MQTT server domain name or IP address
cloudmqtt.usr.cn
Port
MQTT server port
1883
Client ID
MQTT client identifier. Not repeatable when connected to the
same MQTT server.
123456
Username
Username for MQTT connection authentication
admin
Password
Password for MQTT connection authentication
admin
Interval of
Reconnection
Interval between next reconnection after MQTT disconnection,
unit: s.
5
MQTT heartbeat time
MQTT protocol heartbeat time, unit: s.
Note: Alibaba Cloud requires that the heartbeat can be set within
30--1200 seconds, and it is recommended to set it to 300 seconds
when connecting to Alibaba Cloud.
60
MQTT serial trans
mode
Transparent mode, distribution mode
Transparent mode
Clean session
MQTT protocol connection flag, used to control the lifetime of
session state.
Enable
Will messages enable
MQTT connection flag, when the network connection is closed, the
Enable