Ebyte E840-DTU User manual

GPRS Serial Server
E840-DTU（GPRS-03）
User Manual
This manual may be modified based on product upgrade, please refer to the latest version.
All rights to interpret and modify this manual belong to Chengdu Ebyte Electronic Technology Co., Ltd.

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
1
Version
Date
Description
Issued by
1.00
2018/08/02
Initial version
huaa
E840-DTU (GPRS-03) is a product developed for serial port devices and network servers to transmit data through each other through the network. This product
uses the standard AT command, which enables transparent transmission between devices and servers. The cloud platform built by Ebyte can realize the free
networking mode. The E840-DTU (GPRS-03) is an industrial grade quad-band GSM/GPRS digital radio.
This chapter is a quick introduction to the E840-DTU (GPRS-03) product. It is the easiest hardware environment to test the E840-DTU (GPRS-03) network
transmission function, that is, to realize the serial device (here, the computer) to the network server ( TCP test tool instead of) network transparent transmission.
Feature
Able to meet almost all M2M application needs;
Support data transparent transmission, support TCP, UDP network protocol, support heartbeat package, registration package;
Support serial port caching function, the serial port data can be cached locally before the connection is established with the server;
Maximum GPRS data downstream rate is 85.6kbps, maximum upstream rate is 85.6kbps;
Support TCP/UDP/FTP/PPP/HTTP/NTP/MMS/SMTP/PING，code format include CS-1、CS-2、CS-3 and CS-4；
Support 8~28V wide voltage power supply, adopt DC power supply and terminal terminal power supply mode;
The RS485 circuit uses electrical isolation, lightning protection, and surge protection to provide immunity to interference.

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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Contents
FEATURE.............................................................................................................................................................................................. 1
1. INTRODUCTION.............................................................................................................................................................................3
1.1 BRIEF INTRODUCTION................................................................................................................................................................. 3
1.1. PARAMETERS............................................................................................................................................................................... 3
1.2. INTERFACE DESCRIPTION............................................................................................................................................................ 4
1.3. PIN DEFINITION..........................................................................................................................................................................5
2. QUICK START..................................................................................................................................................................................5
2.1. DEVICES PREPARATION...................................................................................................................................................................5
3. OPERATING MODE........................................................................................................................................................................7
3.1 TRANSPARENT TRANSMISSION.........................................................................................................................................................7
3.2 AT MODE...................................................................................................................................................................................... 8
3.3 MODE SWITCH...............................................................................................................................................................................8
4. NETWORK FUNCTION.................................................................................................................................................................. 8
5. EBYTE IOT PLATFORM FUNCTION............................................................................................................................................. 8
6. AT COMMAND...............................................................................................................................................................................8
7. NOTES............................................................................................................................................................................................14
8. IMPORTANT STATEMENT..........................................................................................................................................................15
9. ABOUT US.....................................................................................................................................................................................15

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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1. Introduction
1.1 Brief Introduction
E840-DTU (GPRS-01) is a new generation wireless data transceiver developed by Ebyte. The software of this product is fully functional and covers most of the
conventional application scenarios. Users can realize the transparent transmission of bidirectional data from serial port to network server through simple setting.
The radio is powered by the DC power supply or RS485 terminal in the power supply section. It is powered by a wide voltage of 8.0V to 28.0V and supports
5.0V power supply. It only supports mobile and Unicom 2G cards. RS485 and RS232 circuits use electrical isolation schemes, which have anti-interference ability and
can be used in some environments with strong electromagnetic interference, such as some power industries.
1.2 Parameters
Item
Value
Description
Characteristic Features
Support Band
Quad Band: GSM850, EGSM900, DCS1800, PCS1900
Module automatically searches for frequencies
Band selection can be set by AT command
Compliant with GSM Phase 2/2+
GPRS connection characteristic
GPRS multi-slot class 12 (default)
GPRS multi-slot class 1~12 (configurable)
GPRS mobile station class B
GPRS data feature
GPRS data downstream transmission: up to 85.6kbps
GPRS data upstream transmission: up to 85.6kbps
Encoding format: CS-1, CS-2, CS-3 and CS-4
Support for PAP (Password Authentication Protocol) protocols commonly used for PPP
connections
Support is usually used for CHAP (Interrogation Handshake Authentication Protocol) protocol
Embedded protocol: TCP/UDP/FTP/PPP/HTTP/NTP/MMS/SMTP/PING, etc.
Support for unstructured supplementary data services (USSD)
Hardware Features
Antenna
SMA
Data interface
RS485 / RS232
Baud rate
1200bps ~115200bps，default：115200bps
TX power
Class 4 (2W)： GSM850 and EGSM900
Class 1 (1W)： DCS1800 and PCS1900
AT command format
Ebyte general AT command
3GPP frequency
1 Timeslot
2 Timeslot
4 Timeslot
CS-1
9.05kbps
18.1kbps
36.2kbps
CS-2
13.4kbps
26.8kbps
53.6kbps
CS-3
15.6kbps
31.2kbps
62.4kbps
CS-4
21.4kbps
42.8kbps
85.6kbps

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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1.3 Interface Description

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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1.3 Pin Definition
Pin NO.
Name
Description
1
RS232
RS232 interface
2
485_A
Side A of eternal interface for other RS485 devices
3
485_B
Side B of eternal interface for other RS485 devices
4
GND
Ground
5
VCC
Power supply 8V-28V DC
6
PWR
Power indicator
7
WORK
UART communication indicator
8
NEL
Radio network working indicator, no light: Initializing, slow flashing: access to the base station, fast flashing:
initialization is not successful, always on: access server
9
DC8~28V
Power adaptor interface, range: 8~28V
10
RST
Reset（downward，reset）
11
Restore
The radio operating DIP switch (downward, factory reset) needs to be operated in 3s-10s.
12
SIM
For SIM card
13
ANT
Antenna （SMA-K ，50Ω impedance match）
2. Quick start
2.1 Devices preparation
Please get UART, SIM card, sucker antenna and etc. ready according to the recommended circuit before test.
One piece of E840-DTU(GPRS-03)
One piece of 12V power adaptor

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Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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USB to RS485 adaptor or USB to RS232 adaptor(optional)
GPRS sucker antenna
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 +++ (except for AT
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.

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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4、 After the base station is connected, the NET light is always on to indicate that the server is connected, and transparent transmission is
possible at this time.
5、 User can also use the Ebyte cloud platform for any networking operation. For details, please refer to the operation manual of Ebyte Cloud
Platform.
3. Operating mode
3.1 Transparent transmission
After power-on, the radio works in transparent mode by default, and automatically starts the network connection. When the connection is established with
the server, any data received by the serial port will be transparently transmitted to the server. At the same time, it can also receive the data from the server. After
receiving the server data, the module will output directly through the serial port. The maximum length of data supported by this module is 512 bytes.
This module supports one-channel Socket connection. The user can configure it as TCP Client or UDP Client. In transparent transmission mode, the received
serial port data will be directly transmitted to the network server, and the received network server data will be directly output through the serial port.

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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3.2 AT mode
In this mode, the serial port data is regarded as an AT command. The user can configure the module through a valid AT command. If the format is wrong, the
relevant error code will be prompted.。
3.3 Mode switch
In the transparent transmission mode, after the serial port receives the "+++" frame data, the RX pin receives any AT command within 3 seconds, and the
mode switches to the AT mode. In AT mode, one can send AT+EXAT<CR><LF> to switch to transparent transmission mode.。
4. Network function
a) Short connection: In TCP Client mode, the short connection function is enabled. If there is no data reception in the serial port or network port within
the set time, the network connection will be automatically disconnected. The short connection function is turned off by default. The connection time
can be set from 2 to 255 seconds. When set to 0, the short connection function is disabled.
b) Registration package: The registration package is closed by default. 4 options include: physical address when connecting, send custom data when
connecting, add physical address before each packet of data, add custom data before each packet of data. The maximum data length for customize
registration package is 40 bytes (when set to HEX format, the maximum length is 20 bytes)
c) Heartbeat packet: In the idle state of network communication, the heartbeat packet is used for network state maintenance. The heartbeat period can
be set from 0 to 65535 seconds, and the maximum length of the heartbeat packet is 40 bytes (when set to HEX format, the maximum length is 20
bytes). Supports two types of heartbeats, network heartbeat, serial heartbeat. User selects network heartbeat, starts timing when in communication idle,
and sends heartbeat packets to the server according to the configured heartbeat period. User selects the serial port heartbeat, start timing when in
communication idle, and send heartbeat packets to the serial port according to the configured heartbeat period.
Clear the cache: Before the connection to the server is established, the data received by the serial port will be cached. When the connection with the
server is established, you can choose whether to clear the cached data. By default, the cache is cleared.
The maximum packet length of the local cache is 256 bytes.
5. Ebyte IoT platform function
AT+EBTIOT command is used to set whether the module enables the transparent transmission function of the Ebyte cloud platform, after the device is
turned on, the information such as the heartbeat and registration package configured by the user will be invalid. The user only needs to set the forwarding
relationship of the corresponding device to the platform to implement the transparent transmission. For details of the related operations, please refer to the
"Transparent Transmission Guide for Ebyte Cloud Platform ".
6. AT command
a) Command format：
AT+<CMD>[op][ para1, para2, para3,…]<CR><LF>
AT+：Command prefix
CMD：Control command
[op]：“=”indicate parameter configuration

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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“NULL”indicate parameter query
[para-n]：parameter list
<CR><LF>：Enter, start new line，ASCII 0x0D 0x0A
b) Error code：
Error code
Description
-1
Invalid command format
-2
Invalid command
-3
Invalid Operator
-4
Invalid parameter
-5
Operation not allowed
c)Command set：
Command
Description
REBT
Restart Module
VER
Query version number
INFO
Query device info.
EXAT
Exit AT command mode
RESTORE
Restore factory setting
UART
Set/Query UART parameter
UARTCLR
Set/query whether UART cache is cleared before
module connection
MAC
Set/query MAC address
IMEI
Set/query IMEI
LINKSTA
Set/query SOCK connection
LINKSTA1
Set/query SOCK1 connection
LINKSTA2
Set/query SOCK2 connection
LINKSTA3
Set/query SOCK3 connection
SOCK
Set/query SOCK parameter
SOCK1
Set/query SOCK1 parameter
SOCK2
Set/query SOCK2 parameter
SOCK3
Set/query SOCK3 parameter
REGMOD
Set/query registration package mode
REGINFO
Set/query customized registration package
information（ASCII）
REGINFO1
Set/query customized registration package
information（HEX）
HEARTMOD
Set/query Heartbeat Packet mode
HEARTINFO
Set/Query Customized Heartbeat Packet
Information（ASCII）
HEARTINFO1
Set/query custom heartbeat packet information
(hexadecimal)
HEARTM
Set/query heartbeat time
SHORTM
Set/query short connection time
EBTIOT
Set/Query EBYTE IoT Cloud Platform Enable
CREG
Query whether registered to network
CSQ
Query signal strength
CPIN
Query SIM status

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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d) Command details：
AT+REBT
Function： Restart module
Format： Set
TX：AT+REBT<CR>
Return：<CR><LF>+OK<CR><LF>
Parameter：None
Description: After the command is executed correctly, the module restarts immediately and enters the transparent transmission mode after restarting.
AT+VER
Function： Query firmware version
Format： Set
TX AT+VER<CR><LF>
Return <CR><LF>+OK=<ver><CR><LF>
Parameter：Ver firmware version
description：None
AT+INFO
Function： Query module type and version
Format： Set
TX AT+INFO<CR><LF>
return <CR><LF>+OK=<mod_name>,<hw_ver>,<sw_ver><CR><LF>
Parameter： mod_name module name
hw_ver hardware version
sw_ver software version
description：None
AT+EXAT
Function： exit command mode，enter transparent transmission mode
Format： Set
TX AT+EXAT<CR><LF>
return <CR><LF>+OK<CR><LF>
Parameter：None
Description：After the command is executed correctly, the module is switched from command mode to transparent mode.
AT+RESTORE
Function： Restore factory setting
Format： Set
TX AT+RESTORE<CR><LF>
return <CR><LF>+OK<CR><LF>
Parameter：None
description：None
AT+UART
Function： Set/Query UART parameter
Format： Query
TX：AT+UART<CR>
Return：<CR><LF>+OK=<baudrate>,< parity ><CR><LF>
Set
TX：AT+UART=<baudrate>,< parity ><CR><LF>

GPRS E840-DTU（GPRS-03）User Manual
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Return：<CR><LF>+OK<CR><LF>
Parameter： baudrate Baud rate 1200~921600bps，can be self defined
Parity Parity NON no parity
EVEN even parity
ODD odd parity
Description：None
AT+UARTCLR
Function： Query/set whether the serial port cache is cleared before module is connected
Format： Query
TX：AT+ UARTCLR <CR>
return：<CR><LF>+OK=< sta ><CR><LF>
Set
TX：AT+ UARTCLR =< sta ><CR>
return：<CR><LF>+OK<CR><LF>
Parameters: sta state
ON Clear the serial port cache before connecting.
OFF The serial port cache is not cleared before the connection.
AT+MAC
Function： Query MAC
Format： Query
TX：AT+MAC<CR>
Return：<CR><LF>+OK=<mac><CR><LF>
Parameter： mac MAC address
AT+IMEI
Function： Query IMEI
Format： Query
TX：AT+IMEI<CR>
Return：<CR><LF>+OK=<imei><CR><LF>
Parameter： imei IMEI code
AT+LINKSTA
Function： Query whether TCP link is connected
Format： Query
TX：AT+LINKSTA<CR>
Return：<CR><LF>+OK=<sta><CR><LF>
Parameter： Sta whether TCP link connection is established，Connect(TCP connection)/ Disconnect(TCP cut off)
AT+LINKSTA1
Function： Query whether TCP link is connected
Format： Query
TX：AT+LINKSTA1<CR>
Return：<CR><LF>+OK=<sta><CR><LF>
Parameter： Sta whether TCP link connection is established，Connect(TCP connection)/ Disconnect(TCP cut off)
AT+LINKSTA2

GPRS E840-DTU（GPRS-03）User Manual
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Function： Query whether TCP link is connected
Format： Query
TX：AT+LINKSTA2<CR>
return：<CR><LF>+OK=<sta><CR><LF>
Parameter： Sta whether TCP link connection is established，Connect(TCP connection)/ Disconnect(TCP cut off)
AT+LINKSTA3
Function： Query whether TCP link is connected
Format： Query
TX：AT+LINKSTA3<CR>
return：<CR><LF>+OK=<sta><CR><LF>
Parameter： Sta whether TCP link connection is established，Connect(TCP connection)/ Disconnect(TCP cut off)
AT+SOCK
Function： Set/query the network protocol parameter format.
Format： Query
TX：AT+SOCK<CR>
return：<CR><LF>+OK=<protocol>,<ip>,< port ><CR><LF>
Set
TX：AT+SOCK=<protocol>,<ip>,< port ><CR>
return：<CR><LF>+OK<CR><LF>
Parameter： protocol protocol type， TCPC / UDPC
TCPC corresponding TCP client
UDPC corresponding UDP client
ip The IP address or domain name of the target server when the module is set to "CLIENT"
port Server port number, in decimal, less than 65535.
AT+REGMOD
Function： Set the query registration package mechanism.
Format： Query
TX：AT+REGMOD<CR>
return：<CR><LF>+OK=<status><CR><LF>
Set
TX：AT+REGMOD =<status><CR>
return：<CR><LF>+OK<CR><LF>
Parameter：status registration package mechanism
EMBMAC adds MAC/IMEI as registration packet data before each packet sent to the server.
EMBCSTM adds custom registration package data before each packet is sent to the server.
OLMAC sends a MAC/IMEI registration packet only when it is first linked to the server.
OLCSTM sends a user-defined registration package only the first time it is linked to the server.
OFF Disables the registration of the packet mechanism.
AT+REGINFO
Function： Set the query custom registration package content
Format： Query
TX：AT+ REGINFO <CR>
return：<CR><LF>+OK=<data><CR><LF>

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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Set
TX：AT+ REGINFO =<data><CR>
return：<CR><LF>+OK<CR><LF>
parameter：data ASCII code within 40 bytes
AT+HEARTMOD
Function： Set/query heartbeat packet mode.
Format： Query
TX：AT+ HEARTMOD<CR>
return：<CR><LF>+OK=<mode><CR><LF>
Set
TX：AT+ HEARTMOD=<mode><CR>
return：<CR><LF>+OK<CR><LF>
Parameter：mode
NET network heartbeat packet
UART UART heartbeat packet
AT+HEARTINFO
Function： Set/query heartbeat packet data
Format： Query
TX：AT+ HEARTINFO<CR>
return：<CR><LF>+OK=<data><CR><LF>
Set
TX：AT+ HEARTINFO=<data><CR>
return：<CR><LF>+OK<CR><LF>
parameter：data ASCII code heartbeat packet data within 40 bytes
AT+HEARTM
Function： Set/Query short heartbeat time
Format： Query
TX：AT+ HEARTM <CR>
return：<CR><LF>+OK=<time><CR><LF>
Set
TX：AT+ HEARTM =<time><CR>
return：<CR><LF>+OK<CR><LF>
parameter：time heartbeat time，0 off，1～65535 seconds
AT+SHORTM
Function： Set/Query short connection time
Format： Query
TX：AT+ SHORTM<CR>
return：<CR><LF>+OK=<time><CR><LF>
Set
TX：AT+ SHORTM=<time><CR>
return：<CR><LF>+OK<CR><LF>
parameter： time short connection time，0 off，2-255 seconds

GPRS E840-DTU（GPRS-03）User Manual
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AT+EBTIOT
Function： Set/query the ebyte IoT platform.
Format： Query
TX：AT+EBTIOT <CR>
return：<CR><LF>+OK=<ctrl><CR><LF>
Set
TX：AT+EBTIOT =<ctrl><CR>
return：<CR><LF>+OK<CR><LF>
Parameter: ctrl IoT Function Switch, 0 off / 1 on.
Note: After the Internet of Things cloud function is turned on, the module is automatically connected to the Ebyte IoT platform, ignoring the
sock configuration, registration package, and heartbeat package Function.
AT+CSQ
Function： Query signal strength
Format： Query
TX AT+CSQ<CR><LF>
return <CR><LF>+OK=<csq><CR><LF>
parameter： csq signal strength
Description： None
AT+CREG
Function： Check if it is registered to the carrier.
Format： Set
TX AT+CREG<CR><LF>
Return <CR><LF>+OK=<creg><CR><LF>
Parameter： creg
1 Network registered
2 Network not registered
Description： None
AT+CPIN
Function： Query SIM status
Format： Set
TX AT+CPIN<CR><LF>
return <CR><LF>+OK=<cpin><CR><LF>
Parameter： cpin
1 SIM card detected
0 SIM card not detected
Description： None
7. Notes
After the module is powered on, it will be automatically initialized. After the initialization is successful, it will automatically establish a connection with the
configured network server. After the connection is successful, the NET light will be on. If the NET light has been flashing slowly, the module is initialized
successfully, but it has been unable to communicate with the server. In this case, check whether the module network server parameter configuration is
correct.
After the module is powered on, it cannot be initialized successfully. After a short time, the NET light flashes quickly. At this time, check whether the module is
installed properly, whether the SIM card is properly inserted, whether the SIM has failed, and whether the module radio antenna is properly connected.

GPRS E840-DTU（GPRS-03）User Manual
Copyright ©2012–2017, Chengdu Ebyte Electrical Technology Co., Ltd.
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8. Important Statement
1. CDEBYTE reserves the right of final interpretation and modification of all the contents of this manual.
2. As the hardware and software products continuously improving, this manual may subject to change without notice, please refer
to the latest version.
3. Everyone is responsible for protecting the environment: to reduce the use of paper, we only provide electronic documents of the
English manual, if necessary, please go to our official website to download.
9. About Us
CDEBYTE after-sales technical support: [email protected]
For file download and more product information, please visit:www.cdebyte.com/en/
Thank you for using the CDEBYTE products! Any questions or suggestions, please contact: [email protected]
Tel：[phone] ext. 812
Fax：[phone]
Web：www.cdebyte.com/en/
Address：Innovation Center D347, 4# XI-XIN Road,Chengdu, Sichuan, China