E90-DTU (900SL22-ETH) V2.0 UserManual EN v1.0

Chengdu Ebyte Electronic Technology Co., Ltd.
E90-DTU(900SL22-ETH)_UserManual_EN
E90-DTU(900SL22-ETH)
Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

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Chengdu Ebyte Electronic Technology Co., Ltd. E90-DTU(900SL22-ETH)_UserManual_EN
Contents
1 Product Introduction ....................................................................................................................................................1
2.1 Hardware Preparation Before Use ........................................................................................................... 2
2.2 Software Preparation ................................................................................................................................ 3
2.3 Hardware Connection ...............................................................................................................................4
2.4 Wireless Parameter Configuration ........................................................................................................... 4
2.4.1 Configuring "Serial Radio" ........................................................................................................... 4
2.4.2 Configuring the "Gateway Radio" ................................................................................................ 6
2.5 TCP Server Usage .................................................................................................................................... 7
2.6 TCP client Usage ...................................................................................................................................... 8
2.7 UDP Server Usage ....................................................................................................................................9
2.8 UDP Client Usage .................................................................................................................................. 10
3. Specification and Parameter .....................................................................................................................................12
3.1 General Specifications ............................................................................................................................12
3.2 Wireless Specifications .......................................................................................................................... 13
3.3 Mechanical Dimension Drawing ........................................................................................................... 14
3.4 Pin Definition ......................................................................................................................................... 15
4. Basic Functions of the Product .................................................................................................................................16
4.1 Default parameters ................................................................................................................................. 16
4.2 LORA Section ........................................................................................................................................ 16
4.2.1 Basic Wireless Parameters .......................................................................................................... 16
4.2.2 Broadcast Monitoring ..................................................................................................................17
4.2.3 Fixed Point Sending .................................................................................................................... 17
4.2.4 Relay Mode ................................................................................................................................. 18
4.2.5 Communication Key ................................................................................................................... 19
4.2.6 LBT Enable ................................................................................................................................. 20
4.2.7 WOR Role ................................................................................................................................... 20
4.2.8 Data RSSI Enable ........................................................................................................................20
4.2.9 Channel RSSI Enable ..................................................................................................................20
4.3 Ethernet Part ........................................................................................................................................... 21
4.3.1 IP Acquisition .............................................................................................................................. 21
4.3.2 Device Port ..................................................................................................................................21
4.3.3 Subnet Mask and Gateway Configuration .................................................................................. 22
4.3.4 DNS ............................................................................................................................................. 22
4.3.5 Target IP/Domain Name ..............................................................................................................22
4.4 SOCKET Function ................................................................................................................................. 23
4.4.1 TCP Server .................................................................................................................................. 23
4.4.2 TCP Client ................................................................................................................................... 23
4.4.3 UDP Server ..................................................................................................................................23
4.4.4 UDP Client .................................................................................................................................. 23
4.4.5 HTTP Client ................................................................................................................................ 24
4.4.6 MQTT Client ...............................................................................................................................25
4.4.7 Web Configuration .............................................................................................................................. 28

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4.4.8 Hardware Factory Reset ......................................................................................................................29

5. Advanced Features ....................................................................................................................................................30
5.1 Heartbeat packet ..................................................................................................................................... 30
5.2 Registration Package .............................................................................................................................. 30
5.3 Short Connection ....................................................................................................................................31
5.4 Reconnect After Disconnection ..............................................................................................................31
5.5 Timeout Restart ...................................................................................................................................... 31
5.6 Cache Cleaning .......................................................................................................................................31
5.7 Remote Configuration ............................................................................................................................ 32
5.8 Remote Upgrade .....................................................................................................................................32
5.9 Modbus Gateway ....................................................................................................................................34
5.9.1 Protocol Conversion ....................................................................................................................34
5.9.2 Simple Protocol Conversion ....................................................................................................... 34
5.9.3 Multi-host Mode ..........................................................................................................................35
5.9.4 Storage Gateway ......................................................................................................................... 35
5.9.5 Configurable Gateway ................................................................................................................ 36
5.9.6 Automatic Upload ....................................................................................................................... 38
6. Configuration Method .............................................................................................................................................. 39
6.1 Web Configuration ................................................................................................................................. 39
6.2 Host Computer Configuration ................................................................................................................39
6.3 AT Command Configuration .................................................................................................................. 39
Revision History ...........................................................................................................................................................40

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1 Product Introduction
Brief introduction
E90-DTU (900SL22-ETH) supports adaptive network rate (up to 100m full
duplex), provides six working modes of TCP server, TCP client, UDP server, UDP
client, HTTP client and mqtt client, and supports four-way client connection in
TCP server mode;
Support a variety of Modbus gateways, which can simply exchange Modbus

TCP data and Modbus RTU data, record and send read instructions, and actively
upload to the server through pre stored instructions;
Wireless communication adopts Lora direct sequence spread spectrum technology, which will bring longer
communication distance, and has the advantages of centralized power density and strong anti-interference ability. With
software FEC forward error correction algorithm, it has high coding efficiency and strong error correction ability. In the
case of sudden interference, it can actively correct the disturbed data packets, greatly improve the reliability and
transmission distance, and help users efficiently complete the transparent transmission of long-distance data. Users can
make relevant configuration through web pages;
Features
 Using the latest LoRa technology, farther distance and more powerful performance than traditional LoRa digital
radio;
 Using military-grade LoRa modulation technology, with data encryption, and the sub-packet length can be set;
 Support LBT function, the radio station waits for transmission according to the current environmental noise
intensity. Improve the communication success rate of the radio in harsh environments;
 Support wireless sending of command data packets, remote configuration and communication encryption;
 It can realize multi-level relay networking, effectively expand the communication distance, and realize
ultra-long-distance communication;
 Industrial grade design, which can work in the environment of -40℃～+85℃, wide voltage input (DC 8～
28V);
 All aluminum alloy shell, compact size, easy installation, good heat dissipation;
 Perfect shielding design, good electromagnetic compatibility, strong anti-interference ability;
 RJ45 adaptive 10/100M Ethernet interface;
 Support multiple working modes (TCPS, TCPC, UDPS, UDPC, HTTPC, MQTTC);
 Support three configuration methods: configuration tool, web page and AT command;
 Server mode supports up to 6 socket connections;
 Support DHCP function;
 Support DNS (domain name resolution), and custom domain name resolution server;
 Support a variety of Modbus gateways (simple protocol conversion, multi-host mode, storage gateway,
configurable gateway, etc.);
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 Supports quick access to Alibaba Cloud, Baidu Cloud, OneNET, Huawei Cloud, and standard MQTT servers
of version 3.1;
 Support HTTP protocol (GET/POST request);
 Support timeout restart function, time can be customized;
 Support short connection function, short connection interval time customization;
 Support heartbeat package and registration package function;
 Support serial port cache cleaning function;
 Support access to the external network, local area network, and virtual serial port tools;
 Support hardware reset to factory settings;
 Support online upgrade function.
2. Quick Start
2.1 Hardware Preparation Before Use
Take the transparent transmission betweenE90-DTU (900SL22-ETH) and E90-DTU (900SL22-ETH) as an example.
In order to test the E90-DTU (900SL22-ETH) , the following hardware is required:
 One PC with network port;
 OneE90-DTU (900SL22-ETH) (or other products in the same series of frequency bands), hereinafter referred to
as "gateway radio"；
 One E90-DTU (900SL22) digital radio, hereinafter referred to as "serial radio" (for example, if necessary,
buy it separately);
 TX915-JKD-20P 2 antennas (inner thread, inner needle);
 Two DC12V-1A power adapters;
 One network cable;
 One USB to RS-485 serial cable;
PC E90-DTU (900SL22-ETH) E90-DTU(900SL22)

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Network Cable DC12V-1A Power Adapter*2 Serial Cable TX915-JKD-20P*2
2.2 Software Preparation
The product details on the Ebyte official website provide the download of the network debugging assistant "NetAssist"
and the serial port assistant "XCOM", as shown in the following figure. Official website address: https://www.ebyte.com.
Download the configuration tool corresponding to the product details, use "Ebyte Network Configuration Tool" for
"Gateway Radio", and "E9x-DTU(xxxSLxx)" for "Serial Radio".

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2.3 Hardware Connection
Connect the antenna to the E90 radio and connect to the power supply (DC: 8~28V), RS485 connection, network cable
connection:
Up: "Gateway Radio" on

Connect RS-485 for Connect the network cable
Connect the antenna Down："Serial Radio" is
"Serial Radio" for the "Gateway Radio"
connected
2.4 Wireless Parameter Configuration
2.4.1 Configuring "Serial Radio"
Step 1: Turn on the power and connect the USB to RS-485 serial cable (serial cable A is connected to the radio
485_A, serial cable B is connected to the radio 485_B);
Step 2: Check whether the radio is working in configuration mode, if not in configuration mode, configure the DIP
switch to enter configuration mode according to the figure below;
Step 3: Open the configuration host computer "E9x-DTU(xxxSLxx)" and select the corresponding serial port;

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Step 4: "Open Serial Port" and click "Read Parameters", then click "Restore Factory Settings";
Step 5: Configure the baud rate to be 9600, the checksum to be 8N1, the airspeed to be 2.4Kbps, the packet length
to be 240Bytes, etc., as shown in the figure below, click "Write Parameters";

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2.4.2 Configuring the "Gateway Radio"
Step 1: Turn on the power and connect the PC and the "Gateway Radio" with a network cable;
Step 2: Perform factory configuration on the "Gateway Radio", press and hold the Reload button until the indicator
lights are all on;
Step 3: Modify the IPv4 configuration of the PC, use a static IP, and ensure that the "gateway radio" and the PC are
in the same network segment. The factory default IP is 192.168.4.101, so configure the static IP of the PC as
192.168.4.100 as shown in the following figure:
Step 4: Use "Ebyte Network Configuration Tool" or web page configuration;
Step 5: Configure the wireless parameters as shown in the figure above, the host computer clicks "Save
Configuration" and then clicks "Restart Device", click Submit for web page configuration, enter the configuration
key: 123456, and wait for the configuration to complete;
【Note】
For browsers that do not support IE kernel, you can use Firefox, GOOGLE, the latest Edge and other browsers;
If the host computer fails to search for the device, first check whether the network cable is normally connected, and
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then check whether the host computer is turned on several times in the local area network. If it still cannot be used
normally, you can close the firewall and restart the host computer;
Do not enter the web page in communication mode, otherwise the device will enter the configuration mode, and
you can only exit the configuration mode by submitting data or restarting the device.
2.5 TCP Server Usage
Configure the Ethernet parameters of the "gateway radio", the host computer and web page are configured as
follows:
The network assistant (NetAssist) is connected to the "gateway radio" as shown in the figure below (the LINK
indicator of the device is always on after the connection is successful, if it can be connected but the indicator is not
on, the device is in the configuration mode, which can be released by restarting the device), XCOM is connected to
the "serial gateway" ":
Data sending and receiving test:

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2.6 TCP client Usage
Configure the Ethernet parameters of the "Gateway Radio", the host computer and web page are configured as
follows:
The network assistant (NetAssist) is connected to the "gateway radio" as shown in the figure below (the LINK
indicator of the device is always on after the connection is successful), and the XCOM is connected to the "serial
gateway":
Data sending and receiving test:

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2.7 UDP Server Usage
follows:
After the configuration is completed, the LINK indicator of the device is always on, and the NetAssist is connected
to the "gateway radio" as shown in the figure below:

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Data sending and receiving test (in UDP server mode, data must be sent by PC first, then UDP can dynamically
adjust the destination address, and the data sent by serial port can only be received by the UDP of the last
communication):
2.8 UDP Client Usage
follows:

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After the configuration is completed, the LINK indicator of the device is always on, and the NetAssist is connected
to the "gateway radio" as shown in the figure below:
Data sending and receiving test The data sent by the serial port will only be received by UDP
(192.168.4.100:8887):

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3. Specification and Parameter
3.1 General Specifications
No. Item Specification

1 Supply Voltage 8V~28VDC, recommended 12V or 24V power supply
Network Port
2 Standard RJ45, support 10/100Mbps
Specifications
Network
3 IP, TCP/UDP, ARP, ICMP, IPv4, MQTT, HTTP
Protocol
4 Socket Mode TCP Server, TCP Client,
TCP Server
5 UDP Server, UDP Client,
Connection
6 IP Get Method HTTP Client, MQTT Client
7 DNS Supports up to 6 TCP connections
Domain Name
8 Static IP, DHCP
sServer
User
9 Support
Configuration
Antenna
10 Customizable, default 114.114.114.114
Interface
Operating
11 Web configuration, host computer, AT commands
Temperature
Working
12 SMA
Humidity
13 Size -40 ~ +85℃, industrial grade
14 Average Weight 10% ~ 90%, relative humidity, non-condensing
Storage
15 84mm*82mm*25mm
Temperature

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3.2 Wireless Specifications
Performance
Main Specification Remarks
Minimum Typical Value Maximum
The probability of burning at
Blocking Power（dBm） - - 10
close range is small
Support ISM frequency
Working Frequency Band
868.125 - 930.125 band, 0 ～ 64; Default: 40,
（MHz）
Channel Spacing: 250K
Power Emission Current 84.1mA @ 12V
Consu （mA） 42.9mA @ 24V Instantaneous power
mptio Receive Current 10.3mA @ 12V consumption
n （mA） 6mA @ 24V
High (22dBm), Medium
(17dBm), Low (13dBm),
Very low (10dBm)
Except for "high", the other
transmit power is the
Maximum transmit power reference value, the actual
21.5 22.0 22.5
（dBm） value may be different, and
reducing the transmit power
will not reduce the power
consumption of the device, it
is recommended to use the
maximum power
Receive Sensitivity（dBm） -146 -147 -148 The default air rate is
2.4kbps,User-configured
Air rate（bps） 0.3k 2.4k 62.5k (0.3、1.2、2.4、4.8、9.6、
19.2、38.4、62.5Kbps)
Clear and open environment,
antenna gain 5dBi, antenna
Reference distance 5000m
height 2.5 meters, air rate
2.4 kbps
Can be set to send
Packet Length 240 Btye 32/64/128/240 bytes in
packets
Receive length 1000 Btye
Modulation A new generation of LoRa

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3.3 Mechanical Dimension Drawing
Size:mm

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3.4 Pin Definition
No. Item Function Description

Power interface, 8 ～ 28V DC female socket (inner needle
1 DC_IN
diameter 2.0mm, hole diameter 6.4mm)
2 ETHERNET Ethernet interface, standard RJ45 interface
3 PWR Power Indicator
4 LINK connection established indicator
5 DATA Serial port transceiver indicator
6 ANT SMA antenna interface, male screw female
7 Reload Reset to factory settings button

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4. Basic Functions of the Product
4.1 Default parameters
Category Item Value

Module address 0
Channel 40
Network ID 0
Air rate 2.4Kbps
Transfer method Transparent transmission
Packet length 240 Bytes
LORASpecs WOR role Close
WOR cycle 2000ms
Communication key 0
LBT enable Disabled
Relay enable Disabled
Data RSSI Disabled
Channel RSSI Disabled
How to get IP Static
Native port 8886
Native IP 192.168.4.101
Subnet mask 255.255.255.0
Network Specs Gateway 192.168.4.1
DNS server 114.114.114.114
Web access port 80
Network working
TCP Server
mode
4.2 LORA Section
4.2.1 Basic Wireless Parameters
Channel: The devices that need to communicate should work on the same channel, and the current working
frequency band can be calculated according to the channel value;
Working frequency = lowest frequency band + channel value * channel spacing
Module address: The transparent transmission should ensure that the addresses of the devices that need to
communicate are the same. In the fixed-point mode, different devices on the same channel are distinguished. The
relay mode is used to configure the relay address of the data, and the configuration range is 0 to 65535;
Network ID: Transparent transmission should ensure that the network IDs of the devices that need to communicate
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are the same. In relay mode, it is used to distinguish the destination of data. The configuration range is 0 to 255;
Airspeed: Ensure that the airspeeds of the devices that need to communicate are the same;
Packet length: ensure that the equipment that needs to communicate is the same, can configure 32, 64, 128, 240
Bytes, the default is 240 Bytes;
4.2.2 Broadcast Monitoring
Set the DTU wireless address to 0xFFFF: it can monitor the data transmission of all modules on the same channel;
the sent data can be received by modules with any address on the same channel, thus playing the role of
broadcasting and monitoring.
4.2.3 Fixed Point Sending
Support address function, the host can transmit data to any address, any channel module, to achieve networking,
relay and other applications: For example: module A needs to send data to module B (address 0x00 05, channel
0x05); transmit data AA BB CC (HEX: 41 41 20 42 42 20 43 43), its communication format is: 00 05 05 41 41 20
42 42 20 43 43, where 00 05 is the address of module B, and 05 is the channel of module B, then module B can
receive to AA BB CC (other stations do not receive data).
For example, configure the device (DTU_1) as the parameters in the figure, connect the PC to the "gateway radio"
and refer to "Quick Start", (DTU_2) is the same frequency band as the "serial radio" (need to be purchased
separately), and also configure the corresponding parameters in the figure.

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Fixed-point sending demo:

To send DTU_1 to DTU_2, you need to add 00 05 05 (HEX) before the data;
To send DTU_2 to DTU_1, add 00 0A 0A (HEX) before the data;
4.2.4 Relay Mode
No. Relay Mode Description

After setting the relay mode through the configuration mode, switch to the general mode, and the
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relay starts to work.
In relay mode, the "module address" no longer takes effect as an address parameter, but is used as a
2 network ID (NETID) for forwarding pairing. If one network is received, it is forwarded to the other
network. The network ID (NETID) of the repeater itself is invalid.
In relay mode, the relay module cannot send and receive data, and cannot perform low-power
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operation.

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Relay networking rules description：

1. Forwarding rules, the relay can forward data between two network IDs (NETIDs) in both directions.
2. In relay mode, "module address" no longer takes effect as the address parameter but as the network ID (NETID)
for forwarding pairing.
As shown in the figure:
①First-level relay
"Node 1" NETID is 08 (0x08).
"Node 2" NETID is 33 (0x21).
The module address of relay 1 is 2081 (0x0821, ADDH: 0x08, ADDL: 0x21).
So the signal sent by node 1 (0x08) can be forwarded to node 2 (0x21)
At the same time, the addresses of node 1 and node 2 are the same, so the data sent by node 1 can be received by
node 2.
②Secondary relay
The address of relay 2 is 8453 (0x2105, ADDH: 0x21, ADDL: 0x05).
So relay 2 can forward relay 1's data to network NETID: 05 (0x05).
Therefore, node 3 and node 4 can receive the data of node 1. Node 3 outputs data normally, and node 4 has a
different address than node 1, so no data is output.
③Two-way relay
As shown in the configuration: the data sent by node 1 can be received by nodes 2 and 3, and the data sent by nodes
2 and 3 can also be received by node 1.
4.2.5 Communication Key
The web page configuration is always displayed as 0 (the configuration range is 0 to 65535), and the
communication key is used for user encryption to avoid the interception of wireless data in the air by similar
modules. The DTU will use these two bytes as a calculation factor to transform and encrypt the wireless signal in
the air.
Web page configuration needs to configure the key every time, otherwise the device will encrypt the
communication data with 0.
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The AT command and the host computer can query the communication key of the current device, but the web page
configuration cannot query the communication key and returns 0.
4.2.6 LBT Enable
DTU has the function of Listen before talk (LBT). After this function is enabled, it will actively monitor the
channel environment noise before wireless data transmission. If the noise exceeds the threshold, the transmission
will be delayed. This function can greatly improve the communication success rate of DTU in harsh environments. ,
which can be used for network transmission and anti-collision processing, but may cause data delay. The maximum
stay time of LBT is 2 seconds.
4.2.7 WOR Role
WOR closed. The DTU works in the transmission mode, the data input by the user through the Ethernet, the DTU
will start the wireless transmission. The wireless receiving function is turned on, and the wireless data is output
through Ethernet after receiving the wireless data.
WOR transmitter. The DTU transceiver is turned on, and a wake-up code for a certain period of time is added when
transmitting data.
WOR receiver. The DTU cannot transmit data and works in the WOR monitoring mode. The longer the WOR
monitoring interval period, the lower the average power consumption, but the greater the data delay, the sender and
receiver must be consistent (very important).
4.2.8 Data RSSI Enable
It means the signal strength indicator function. When enabled, the DTU radio receives data and will follow the user
data with an RSSI strength byte (in hexadecimal). It can be used to evaluate signal quality, improve communication
networks, ranging, and can be used to manually implement LBT functions.
4.2.9 Channel RSSI Enable
When enabled, the register can be read by sending the C0 C1 C2 C3 command in transmit mode or WOR transmit
mode.
 Register 0x00: Current ambient noise RSSI;
 Register 0x01: RSSI when data was last received. (The current channel noise is: dBm =-RSSI/2);
 Command format: C0 C1 C2 C3 + start address + read length;
 Return: C1 + address + read length + read valid value; such as: send C0 C1 C2 C3 00 01
 Return C1 00 01 RSSI
Demonstration instructions, open the data RSSI and channel RSSI, first send 0x31 with the remote device, the
gateway receives the data (0x30) + RSSI (0xCE), and then query the channel RSSI and data RSSI through the
command C0 C1 C1 C2 C3 00 02 (HEX) The results are as follows As shown in the figure:

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4.3 Ethernet Part
4.3.1 IP Acquisition
Dynamic acquisition (DHCP):
The dynamic acquisition device will automatically obtain the IP address and subnet mask from the router and
synchronize the router's gateway and DNS server. Therefore, in the dynamic acquisition mode, only the working
mode and target parameters of the device can be configured.
Static configuration (STATIC):
You need to manually configure the device's IP (factory default: 192.168.3.7), subnet mask (factory default:
255.255.255.0), gateway (factory default: 192.168.3.1), DNS server (factory default: 114.114.114.114) and other
parameters , the configuration is to ensure that the communication devices are located in the same network segment
and to avoid IP conflicts, otherwise the device cannot pass through and configure the web page normally.
4.3.2 Device Port
Random Port:
TCP client, UDP client, HTTP client, MQTT client can configure the local port to 0 (use random local port), and
server mode cannot use random port, otherwise the client cannot establish the connection correctly (the device does
not correctly port listening).
Using a random port connection can quickly re-establish the connection when the device disconnects from the
server unexpectedly, preventing the server from rejecting the connection due to four waves of incompleteness. It is
recommended to use a random port in client mode.
When the device configures the TCP client, HTTP client, and MQTT client mode on the web page, it will
automatically configure a random port, which can be customized to cancel.

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Static Port:
Device fixed port (factory default: 8886), TCP server mode device listens to the configured port, accepts client
connection requests and establishes a connection for data communication, TCP client mode device fixed port
initiates connection requests.
4.3.3 Subnet Mask and Gateway Configuration
The subnet mask is mainly used to determine the network number and host number of the IP address, to indicate the
number of subnets, and to determine whether the module is in the subnet.
The subnet mask must be set. Our commonly used class C subnet mask: 255.255.255.0, the network number is the
first 24 bits, the host number is the last 8 bits, the number of subnets is 255, and the module IP is in the range of
255 within this subnet, the module IP is considered to be in this subnet.
Gateway refers to the network number of the network where the current IP address of the module is located. If a
device such as a router is connected to the external network, the gateway is the router.
4.3.4 DNS
The DNS is to translates domain names into network-recognized IP addresses through DNS servers. The DNS
server address of this product supports user-defined, and can realize domain name resolution through a custom
domain name resolution server in the event of an abnormal domain name server. The device will report the
resolution to the custom domain name resolution (DNS) server during domain name resolution. Request, return the
device connection parameters (usually the IP address) after the parsing is completed.
In DHCP mode, the domain name resolution (DNS) server address is automatically obtained (synchronized with the
router's domain name resolution address) and cannot be customized.
In static IP mode, the factory default address of the domain name resolution (DNS) server is 114.114.114.114,
which can be customized by the user.
4.3.5 Target IP/Domain Name
The target IP parameter can automatically identify whether the configuration parameter is an IP address or a
domain name input, and the domain name input supports a maximum of 128 characters for configuration.

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4.4 SOCKET Function
4.4.1 TCP Server
In TCP Server mode, the device listens to the local port, accepts the client's connection request and establishes a
connection for data communication. When the Modbus gateway function is disabled, the device sends the data
received by the serial port to all client devices that establish connections with the device, and supports up to 6
clients. After the Modbus gateway function is enabled, the non-Modbus data will be cleared and not forwarded.
Typically used for communication with TCP clients within a local area network.
The connection request is no longer accepted after more than 6 clients, and the web page configuration cannot be
used when the 6 clients remain connected.
4.4.2 TCP Client
When the device is working, it will actively initiate a connection request to the server and establish a connection to
realize the interaction between serial port data and server data.
To use the client, you need to configure the target IP address/domain name and target port accurately.
4.4.3 UDP Server
UDP Server means that the device does not verify the IP address of the data source when it communicates using the
UDP protocol. After receiving a UDP data packet, it saves the source IP address and source port of the data packet,
and sets it as the destination IP and port, so the device only sends data packets to the source IP address and port
where the device received the data last time.
This mode is usually used in scenarios where multiple network devices communicate with this device, and the
frequency is high, and the TCP Server cannot meet the conditions.
Using UDP Server requires the remote UDP device to send data first, otherwise the data cannot be sent normally.
[Note] In UDP mode, the data sent by the network to the device should be less than 512Bit per packet, otherwise it
will cause data loss.
4.4.4 UDP Client
UDP Client is a connectionless transmission protocol that provides transaction-oriented simple and unreliable
information transmission services. There is no connection establishment and disconnection. Only need to configure
the destination IP and destination port to send data to the other party. It is usually used in data transmission
scenarios where there is no requirement for the packet loss rate, the data packets are small and the transmission
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frequency is fast, and the data is to be transmitted to the specified IP.

In UDP Client mode, the device will only communicate with the configured (target IP and target port) remote UDP
devices.
In this mode, the target address is set to 255.255.255.255, and the sent data will be broadcast on the entire network
segment, but the transceiver device needs to ensure that the ports are consistent, and the device can also receive
broadcast data.
4.4.5 HTTP Client
This mode can realize the function of HTTP automatic packet grouping. It provides two modes: GET and POST.
Customers can configure URL, Header and other parameters by themselves, and the device will send packets to
realize fast communication between the digital radio station and the HTTP server. Using HTTP client In terminal
mode, it is recommended to use random ports and enable short connections to save HTTP server resources. The
size of a single request packet is affected by LORA subcontracting. When LORA is configured for 240-byte
subcontracting, the single packet data cannot be larger than 240.
Supports configuring whether to return HTTP protocol headers. The returned data is shown in the following figure:

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Protocol configuration instructions, enable DHCP to configure the HTTP server address and corresponding port
number (the picture below is the host computer, and the picture above is the webpage):
Mode configuration description, take the packet header not returned as an example (the picture on the left is the
configuration of the host computer, and the picture on the right is the configuration of the web page):
4.4.6 MQTT Client
Supports quick access to standard MQTT3.1.1 protocol servers (OneNET, Baidu Cloud, Huawei Cloud, user-built
and other server types) and Alibaba Cloud servers, supports service quality level configuration (QoS 0, QoS 1),
supports super-long text configuration, Convenient and better access to network service operators (server address,
three elements, subscription and publishing addresses support up to 128 characters of configuration).

25
When using the MQTT function, the advanced settings such as short links should be closed as shown in the
following figure (the upper picture is the host computer, and the following picture is the web page configuration):
(1) Select the standard MQTT3.1.1, Baidu Cloud, OneNET, and HUAWEI Cloud configuration can refer to
the configuration shown in the following figure (the left picture is the host computer, the right picture is the
webpage):

26
(2) Alibaba Cloud

Support the use of Alibaba Cloud's "Three Elements" to directly connect to the server to obtain the "Three
Elements" required to connect to Alibaba Cloud, as shown in the figure (only for demonstration cases, users need to
use self-built parameters to connect):
To configure a topic for communication testing:
Select the corresponding product, go to "Custom Topic" under the Topic class list (for details, please refer to
the Alibaba Cloud documentation), click "Define Topic Class", set the name to 1234, and grant publish and
subscribe permissions (for data return pass).
Configure the device connection parameters, as shown in the following figure (the left picture is the host
computer, the right picture is the web page configuration)：
{
"ProductKey": "a1GlhuTU1yN",
"DeviceName": "DEV04",
"DeviceSecret": "xxxxxxxxxxxxxxxxxxxxxxxxxx"
}
Alibaba Cloud server address: ProductKey.iot-as-mqtt.cn-shanghai.aliyuncs.com:1883
Topic for subscription and publication: /a1GlhuTU1yN/DEV04/user/1234

27
Alibaba Cloud MQTT platform communication test:
4.4.7 Web Configuration
The device has a built-in web server, which is convenient for users to set and query parameters through web pages.
The port of the web server can be customized (2-65535), default: 80; Operation method (Microsoft Edge version
94.0.992.50 as an example, does not support IE kernel browser):
(1) . Open the browser, enter the IP address of the device in the address bar, such as 192.168.4.101 (the IP address
and the computer need to be kept on the same network segment, if you cannot use the firewall and try again), if you
forget the local IP, you can use AT commands and configuration software Inquire;
(2) The web page pops up the main interface, and you can query and set relevant parameters;
(3) Click Submit to save the configuration parameters after entering the correct key. The factory default key is:
123456;

28
(4) The progress bar indicates the configuration progress. Do not refresh the web page again after the
configuration is completed (refresh the web page to enter the configuration mode again, you can enter the
communication mode by restarting the device or submitting again);
It can also be opened through the Open Web Configuration button of the configuration software.
[Note] If the port number is modified, the port number should be added to the address input field. For example,
if the web page access port is modified to 8080, the connection web page configuration needs to enter
192.168.4.101:8080 in the address bar.
4.4.8 Hardware Factory Reset
To Press the restore the keys to the factory, need to effectively connect the network cable and power supply. Keep
pressing the Reload pin of the device until the LED indicators are all on to release the keys.

29
5. Advanced Features
5.1 Heartbeat packet
In client mode, users can choose to send heartbeat packets and set the time of heartbeat packets by themselves. The
heartbeat packet can be selected in two modes: network heartbeat packet and serial port heartbeat packet. It
supports hexadecimal and ASCII transmission. This heartbeat packet is not MQTT heartbeat and needs to be turned
off in MQTT client mode. MQTT heartbeat only needs to configure KeepAlive in "MQTT function settings" Time,
it is recommended not to configure less than 60s.
Heartbeat packet sending mode:

(1) The default is to turn off the heartbeat packet mode.
(2), serial port mode -> the device sends heartbeat content to the serial port bus according to the set heartbeat time
interval.
(3) Network port mode -> The device sends heartbeat content to the network port bus according to the set heartbeat
time interval.
Customize heartbeat packet content (maximum support 40 bytes (ASCII) data, 20 bytes (HEX) data)
Customize the heartbeat packet sending interval. When it is set to 0, the heartbeat packet function is disabled. If the
setting value is greater than zero, the heartbeat packet function is enabled. When it is enabled, the range can be set:
(1-65536) seconds.
5.2 Registration Package
In the client mode, the user can choose to send the registration package, and set the registration package time by
definition.
The registration package supports the following modes:

(1) The MAC address (OLMAC) is sent when the network establishes a connection with the device;
(2) The data of the custom registration package sent when the network establishes a connection with the device
(OLCSTM);
(3) After the network and the device are connected, each packet of data sent by the device to the network is
preceded by a MAC address (EMBMAC);
(4) After the network and the device are connected, each packet of data sent by the device to the network is
prepended with custom registration packet data (EMBCSTM);
Custom registration package content (maximum support 40 bytes (ASCII) data, 20 bytes (HEX) data).
[Note] Please do not use special characters (such as ",", "\", "/", etc.) when configuring the registration package on
the web page. The host computer can configure special characters, but it may cause the web page configuration to
be inaccessible.

30
5.3 Short Connection
In client mode, short network connection is supported (this function is disabled by default). TCP short connection is
mainly used to save server resource overhead, and is generally used in multi-point (multi-client)-to-point (server)
scenarios.
The TCP short connection function is applied in the TCP Client mode. After the short connection function is turned
on, it only requests to connect with the server when sending information. The device will automatically disconnect.
When the short link hold time is set to 0, the short link function is turned off. When the setting range is (2-255)
seconds, the short link function is turned on, and the default hold time is 0 seconds (short link is turned off).
5.4 Reconnect After Disconnection
In client mode, after the device is disconnected from the network, it will try to actively connect to the server at the
specified time. If the request times out and the set number of reconnections has not been successfully reconnected,
the device will restart to prevent the device from disconnecting from the network. Unable to restore connection.
Disconnection and reconnection time: The time interval between each attempt of the device to re-establish the
network.
Number of reconnections: The number of times the device tries to re-establish the network, and the cumulative
number of requests reaches the preset value. If the connection is not successful, the device will automatically
restart.
The actual restart time is the network disconnection reconnection period multiplied by the number of reconnections.
It is recommended to use the factory default parameters without special requirements.
5.5 Timeout Restart
Support timeout restart function (default: 300 seconds), this function is mainly used to ensure long-term stable
operation of the device. If data is not sent and received within the set timeout restart time, the device will restart to
avoid the impact of abnormal conditions on communication.
The parameter range of timeout restart time is (60-65535) seconds. If it is set to 0, it means shutdown timeout
restart. The default is 300 seconds.
5.6 Cache Cleaning
The device is in the client mode. When the TCP connection is not established, the data received by the serial port
will be placed in the buffer area. The serial port receiving buffer is 1024 bytes, and the data larger than 1024 bytes
will cover the earliest received data. After the network connection is successful, you can Select to clear the serial
port cache or send the cache through the network through configuration.

31
Enable: The device does not save the data received by the serial port before the connection is established.
Disabled: After the connection is established, the network will receive the serial buffered data.
5.7 Remote Configuration
The remote digital radio can be configured through the remote configuration function of the host computer and web
page. This series of products (E90-DTU(xxxSLxx-ETH)_V2.0) does not support remote configuration. The remote
configuration requires the remote device and the configuration device to be normal communication, otherwise the
configuration command cannot reach the remote device.
After sending the remote configuration command, the indicator DATA flashes twice, the remote device returns
successfully, and the indicator DATA flashes three times. The configuration is sent but the configuration is not
successfully returned.
See the picture below for the remote configuration instructions (the picture above is the remote configuration of the
host computer, and the picture below is the remote configuration of the web page):
[Note] It is recommended that the remote configuration be used in transparent transmission mode and the airspeed
is greater than or equal to 2.4Kbps. For remote configuration on the web page, you need to click "Start Remote
Configuration" first.
5.8 Remote Upgrade
In order to facilitate later maintenance and upgrade functions and replace different firmware, this product supports
online firmware upgrade, and users can upgrade or replace the current firmware through the host computer through
the upgrade firmware provided by our company.
Network upgrade firmware operation steps:

Step 1: Open the host computer, open the device upgrade assistant in the menu bar, and select the required firmware
(the official website provides download firmware);
32
Step 2: Click to search for devices, and click to stop searching after finding the device;
Step 3: Select the corresponding device that needs to be upgraded;
Step 4: Click to start the upgrade, the device indicator flashes, and wait for the upgrade to complete.
[Note] When the device is just powered on, click "Search Device" in the upgrade assistant, the device will enter the
firmware burning state, and it will return to normal mode after power off and restart.

33
5.9 Modbus Gateway
5.9.1 Protocol Conversion
Enabled: Modbus data is checked and non-Modbus data (RTU/TCP) is discarded and not transmitted, and the
Modbus RTU protocol and the Modbus TCP protocol are interconverted.
Disabled: Do not perform protocol conversion but verify Modbus data, discard non-Modbus data (RTU/TCP) and
not transmit.
[Note] Due to the packetization mechanism of LORA wireless modulation, the maximum size of a single packet is
240 bytes. Therefore, in Modbus, a maximum of 117 registers (03, 04 function codes) or 1872 discrete quantities
(01, 02 function codes) can be read continuously at a time.
5.9.2 Simple Protocol Conversion
Convert Modbus RTU data to Modbus TCP data, or convert Modbus TCP data to Modbus RTU data, to realize the
mutual conversion of Ethernet Modbus data and serial port Modbus data.
Simple protocol conversion can work in any mode (TCP client, TCP server, UDP client, UDP server, MQTT client),
no matter what mode it is working in, there can only be one Modbus master.
Simple protocol conversion configuration description (TCP server mode as an example, the left picture is the upper
computer, the right picture is the webpage):

34
5.9.3 Multi-host Mode
There is only one Modbus master station for relatively simple protocol conversion, while the multi-master mode
can handle up to 4 Modbus TCP masters. One request is processed at a time, while the multi-host mode will be
sorted and processed according to the TCP request, and other links will wait), thereby solving the bus conflict
problem (currently only 4 host connections are supported), only supports working in TCP server mode, slave
machine Only in the serial port, otherwise it will not work properly.
With the increase of the number of hosts, the Modbus timeout time should be increased accordingly, and the request
interval should be increased. If multiple hosts are required to make continuous high-speed requests, it is
recommended to use a "storage gateway".
It is recommended to configure "Simple Protocol Conversion" when no multi-channel host is used.

Multi-host mode configuration (the picture above is the host computer, and the picture below is the webpage):
5.9.4 Storage Gateway
The storage gateway not only arbitrates the bus data but also stores the repeated read commands. When different
hosts request the same data, the gateway does not need to query the register status of the RTU device multiple times,
but directly returns the data cached in the storage area. To a certain extent, the multi-host request processing
capability of the gateway is improved, and the time consumed by the entire request process is also shortened. Users
can customize the storage area command polling interval and command storage time according to their needs.
35
As the optimization of multi-host request performance, the storage gateway can only work in the TCP server mode,
which improves the response speed of the network side.
Features:
(1) The gateway has a 3K cache for storing instructions and returning results (reading 10 holding registers as an
example, about 100 instructions and returning results can be stored);
(2) The RTU response time-out automatically clears the cache to ensure the real-time and authenticity of the data;
(3) The polling interval can be customized, 0-65535ms (default: 500ms);
(4) The gateway will poll the RTU device according to the storage time of the instruction used for configuration. If
the MODBUS host does not query the instruction again during the storage time, the gateway will automatically
delete the storage instruction to release the cache;
(5) The first command and control command (05, 06, 0F, 10 function codes) will directly access the RTU device;
(6) Only 01, 02, 03, 04 Modbus function code query result storage is supported;
Storage gateway configuration (the picture above is the host computer, and the picture below is the webpage):
5.9.5 Configurable Gateway
The gateway automatically polls the RTU device registers according to the pre-configured MODBUS commands
(only supports the configuration of the MODBUS read command), and the commands in the non-storage table will
directly operate the RTU device. Frequently read commands can be stored in the gateway in advance, which can
shorten the response time (query configured commands). Due to the above features, the serial port side of the
configurable gateway can only be connected to Modbus slaves.
Instruction storage description (increase, the instruction error and format error cannot be added, the left picture is
the host computer, the right picture is the webpage):

36
Instruction storage description (delete, the picture on the left is the host computer, and the picture on the right is the
webpage):
Instruction storage description (clear, web page and AT command support):
Configurable gateway configuration (the picture on the left is the host computer, and the picture on the right is the
webpage):

37
5.9.6 Automatic Upload
In the client mode (TCP client, UDP client, etc.), the gateway will automatically poll the instructions in the stored
instruction table and upload it to the server. The feedback format (Modbus RTU format or Modbus TCP format)
and the instruction polling interval can be selected according to requirements. (0-65535ms).
For instruction pre-storage, refer to "Configurable Gateway - Instruction Storage Instructions", and automatically
upload the upper computer/web page configuration:
TCP client demonstration (Modbus RTU format on the left, Modbus TCP format on the right):

38
6. Configuration Method
6.1 Web Configuration
You can customize the relevant parameters through the Web setting method. Open the browser, enter the device IP
in the address bar (default: 192.168.4.101), enter the page, you can query and set parameters, and finally click the
"Submit" menu to wait for the page to return to the successful prompt, and it will take effect.
Note: Do not enter the web page configuration during normal use, which may cause data loss. If you enter the web
page configuration, you need to restart to enter the communication mode.
Web page configuration initialization password: 123456, can be customized configuration, only supports 6-bit
uppercase and lowercase letters and numerical configuration.
The webpage configuration requires browsers with newer kernels to work properly, such as Microsoft Edge
(96.0.1054.62), Google chrome (96.0.4664.110), Firefox (95.0.2), etc.
[Note] IE, 360 compatibility mode, QQ browser compatibility mode and other browsers using IE core are not
supported to use web page configuration.
6.2 Host Computer Configuration
Open the configuration tool software, search for devices, double-click the identified device, and the parameter
query configuration interface will pop up. You can customize and modify relevant parameters according to your
needs, then save the configuration, restart the device, and complete the parameter modification.
【Note】:
Do not use multiple host computers in the same local area network environment. Multi-network card industrial
computers need to temporarily disable the use of network cards, otherwise the host computer will not be able to
search for devices normally (the same device is displayed multiple times, no device can be found, etc.)
The host computer shields the wireless network card, so the network cable must be connected to use the host
computer, and the wireless network card can be configured through the web page.
6.3 AT Command Configuration
The query and modification of relevant parameters of the device can be completed through AT command
configuration. For specific AT commands, please refer to "E90-DTU(xxxSLxx-ETH)_V2.0-AT Command Set".
The final interpretation right belongs to Chengdu Ebyte Electronic Technology Co., Ltd.

39
Revision History
Version Date Description Issued by

1.0 2022-06-08 Initial version LC
About us
Technical support: support@cdebyte.com
Documents and RF Setting download link: www.cdebyte.com/en/
Tel：+86-28-61399028
Fax：028-64146160
Web：www.cdebyte.com/en/
Address：Innovation Center B333-D347, 4# XI-XIN Road, Chengdu, Sichuan, China

40

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Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

4.4.8 Hardware Factory Reset ......................................................................................................................29

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Support a variety of Modbus gateways, which can simply exchange Modbus

2.1 Hardware Preparation Before Use

PC E90-DTU (900SL22-ETH) E90-DTU(900SL22)

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Network Cable DC12V-1A Power Adapter*2 Serial Cable TX915-JKD-20P*2

2.2 Software Preparation

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

2.3 Hardware Connection

Up: "Gateway Radio" on

2.4 Wireless Parameter Configuration

2.4.1 Configuring "Serial Radio"

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

2.4.2 Configuring the "Gateway Radio"

Step 4: Use "Ebyte Network Configuration Tool" or web page configuration;

2.5 TCP Server Usage

Data sending and receiving test:

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

2.6 TCP client Usage

Data sending and receiving test:

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

2.7 UDP Server Usage

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

2.8 UDP Client Usage

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

3. Specification and Parameter

3.1 General Specifications

No. Item Specification

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

3.2 Wireless Specifications

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

3.3 Mechanical Dimension Drawing

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

3.4 Pin Definition

No. Item Function Description

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

4. Basic Functions of the Product

4.1 Default parameters

Category Item Value

4.2 LORA Section

4.2.1 Basic Wireless Parameters

4.2.2 Broadcast Monitoring

4.2.3 Fixed Point Sending

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Fixed-point sending demo:

4.2.4 Relay Mode

No. Relay Mode Description

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co., Ltd.

Relay networking rules description：

4.2.5 Communication Key

4.2.6 LBT Enable

4.2.7 WOR Role

4.2.8 Data RSSI Enable

Network Cable DC12V-1A Power Adapter2 Serial Cable TX915-JKD-20P2