1. Introduction

1.1 Brief Introduction

The E95-DTU (400SL22-485) is a wireless data transmission DTU utilizing military-grade LoRa modulation technology. It offers various transmission methods and operates in the 433MHz band. The DTU features a transparent RS485 interface, a plastic shell, a rail-type installation structure, and supports 8-28V voltage input. LoRa spread spectrum technology provides a longer communication distance and strong anti-interference capabilities.

As a communication medium, wireless data transmission stations are applicable in scenarios similar to optical fiber, microwave, and open wire. They provide real-time and reliable data transmission for monitoring signals in private networks under specific conditions, offering low cost, convenient installation and maintenance, strong diffraction ability, flexible network structure, and long coverage. It is suitable for numerous scattered locations and complex geographic environments and can be connected with PLC, RTU, rain gauges, level gauges, and other data terminals.

1.2 Features

• Utilizes the latest LoRa technology, offering greater range and power than traditional LoRa digital DTUs.
• Includes data encryption and allows packet length to be set.
• Features a flame-retardant plastic shell and a guide rail type installation structure for convenient and efficient installation.
• Employs hidden buttons for switching working modes to prevent false triggers, enhancing operational reliability.
• Simple, high-efficiency power supply design supports power supply configuration or line pressure mode, with an 8-28V power supply range.
• Supports LBT (Listen Before Talk) function, allowing the DTU to automatically wait for transmission based on current environmental noise intensity, significantly improving communication success rates in harsh environments.
• Enables wireless sending of command data packets for remote configuration or reading of DTU parameters.
• Includes a communication key function to effectively prevent data interception.
• Supports multi-level relay networking to effectively expand communication distance for ultra-long-distance communication.
• Features a temperature compensation circuit for frequency stability better than ±1.5PPM.
• Operates within a wide temperature range of -40°C to +85°C, making it suitable for various harsh working environments as an industrial-grade product.
• Incorporates multiple protection functions, including power reverse connection protection, over-connection protection, and antenna surge protection, greatly increasing DTU reliability.
• Offers powerful software functionality, allowing all parameters (power, frequency, air rate, address ID, etc.) to be set via programming.
• Provides ultra-low power consumption, with a standby current of only 15mA (lower power consumption in power-saving and sleep modes).
• Includes a built-in watchdog and precise time layout; in case of an abnormality, the DTU automatically restarts and continues to work according to previous parameter settings.

1.3 Quick Start

Step 1: Prepare Devices

Prepare two E95-DTU (400SL22-485) units, a power supply, an antenna, and necessary cables.

Step 2: Connect Antenna and Power

First, install the antenna for the digital DTU, and then connect the power supply. Users can select the appropriate power adapter based on their needs.

Step 3: Connect to Computer

Use a USB to RS-485 converter or other suitable methods to connect the computer to the digital DTU.

Step 4: Configure Serial Port

Start two serial port debugging assistants. Select the serial port baud rate to be 9600bps (default) and the check method to be 8N1 to establish serial port transparent transmission.

Step 5: Switch Working Mode

To switch the working mode, use the Mode button. The mode is indicated by the M1 and M0 LEDs. Press and hold the Mode button for approximately 1 second, then release it to switch modes. The mode switching details are as follows:

Note: The DTU has a power-down save mode function. The factory default setting is transparent transmission mode. Users need to switch to the corresponding mode using the M1 and M0 indicators (changes take effect immediately).

1.4 Parts Description

The E95-DTU device features the following parts:

• 1. Mode Button: Used for switching working modes.
• 2. ANT Interface: SMA-K RF interface with an external thread inner hole.
• 3. DC Terminal: DC power input port (2-pin terminal block).
• 4. RS485 Interface: Standard RS-485 terminal block.
• 5. PWR Indicator: Lights up when the device is powered on.
• 6. TXD Indicator: Flashes when data is being sent.
• 7. RXD Indicator: Flashes when data is being received.
• 8. M0 Indicator: Indicates the working mode.
• 9. M1 Indicator: Indicates the working mode.

2. Interface Description

2.1 Power Interface Description

The E95-DTU can be powered by an 8-28V DC power supply. It is recommended to use a 12V or 24V DC power supply. The wiring port uses a 2-pin terminal connection.

2.2 Communication Interface Description

The E95-DTU utilizes a 3.81 terminal block for RS-485 communication with external equipment.

Note: Communication may be less smooth when connecting the DTU to multiple devices. If this occurs, try connecting a 120Ω resistor in parallel between the 485_A and 485_B terminals.

3. Technical Index

3.1 Model Specification

Note: Performance is based on a sunny, open environment without obstruction, using a 12V/1A power supply, a 5dBi suction antenna, and an antenna height of 2 meters from the ground, with factory default parameters.

3.2 General Specifications

3.3 Frequency Range and Channel Number

Note: For simultaneous one-to-one communication among multiple DTU groups in the same area, it is recommended to set channel spacing above 2MHz for each group.

3.5 Air Speed Class

Note: A higher air speed increases transmission rate but reduces transmission distance. Choose the lowest speed that meets requirements.

3.6 Current Parameter

Note: Reserve more than 50% current margin for the power supply to ensure long-term stable operation.

3.7 Sending and Receiving Length and Data Separate Method

Note:

1. If received data exceeds the single packet capacity, excess data is automatically allocated to the next transmission until completion.
2. Single received data cannot exceed the DTU's buffer capacity.

4. Function Details

4.1 Fixed-point Transmission (Hexadecimal)

In fixed-point transmission, a source DTU sends data with a specific broadcast address and channel. Only target DTUs configured with that specific address and channel will receive the data. Other DTUs on the same channel but with different addresses will not receive the data.

4.2 Broadcast Transmission (Hexadecimal)

In broadcast transmission, a source DTU sends data with a broadcast address (e.g., FFFF) and a channel. All DTUs configured to listen on that specific channel will receive the data, regardless of their individual addresses.

4.3 Broadcast Address

• Example: Set the address of DTU A to 0xFFFF and the channel to 0x04.
• When DTU A acts as a transmitter in transparent transmission mode, all receiving DTUs on channel 0x04 will receive the data, enabling broadcast communication.

4.4 Listening Address

• Example: Set the address of DTU A to 0xFFFF and the channel to 0x04.
• When DTU A is in receiving mode, it can receive all data on channel 0x04, facilitating monitoring purposes.

5. Operating Mode

The E95-DTU supports four working modes. For normal communication without strict low-power requirements, transparent transmission mode (Mode 0) is recommended. This is also the factory default setting.

Note: WOR mode (Mode 1) is primarily for low-power applications and can be ignored if not needed.

5.1 Transparent Transmission Mode (Mode 0)

6. Register Read and Write Control

6.1 Instruction Format

In Configuration Mode (Mode 2: M1 indicator ON, M0 indicator OFF), the following commands are supported (requires 9600, 8N1 serial port format):

6.2 Register Description

7. Relay Network Mode Use

Description of Relay Networking Rules:

1. Forwarding occurs bidirectionally between two NETIDs.
2. In relay mode, ADDH/ADDL act as NETID for forwarding/pairing, not DTU addresses.

Example: Primary Relay

Node 1 NETID: 08. Node 2 NETID: 33. Relay 1's ADDH/ADDL are 08 and 33 respectively. Signal from Node 1 (08) can be forwarded to Node 2 (33). Node 1 and Node 2 share the same address, allowing Node 2 to receive Node 1's data.

Example: Secondary Relay

Relay 2's ADDH/ADDL are 33 and 05 respectively. Relay 2 forwards data from Relay 1 to network NETID 05.

Example: Two-way Relay

Node 3 and Node 4 can receive data from Node 1. Node 4 outputs data normally. Node 3 has a different address from Node 1, so it does not output data. In this configuration, data sent by Node 1 can be received by Nodes 2 and 4, and data sent by Nodes 2 and 4 can also be received by Node 1.

8. PC Configuration Instructions

The E95-DTU (400SL22-485) configuration software interface allows users to switch to configuration mode via the MODE button and quickly configure/read parameters. Parameters like DTU address, frequency channel, network ID, and key are displayed in decimal mode. Ranges: Network Address (0-65535), Frequency Channel (1), Network ID (0-255), Key (0-65535).

When configuring relay mode, note that DTU address and network ID need conversion from decimal to hexadecimal. For instance, if transmitting terminal A has Network ID 02 and receiving terminal B has Network ID 10, the relay terminal R's radio address would be the decimal value of 0x020A, which is 522.

9. Program the DTU

Programming the DTU requires using the configuration software in a specific working mode (Configuration Mode: M1 ON, M0 OFF). If programming fails, verify the DTU's working mode. For simpler parameter adjustments, the E95-DTU configuration software can be used without complex programming.

10. Connection Diagram in Test and Practical Application

A typical setup involves connecting the DTU to a PC (or PLC/RTU) via a cable, an antenna, and a 10-28V DC power supply. The diagram illustrates this connection.

11. Related Products

12. Practical Application

Ebyte DTUs are suitable for various point-to-point and point-to-multipoint wireless data transmission systems, including smart homes, IoT transformation, power load monitoring, distribution automation, hydrology and water regime monitoring, tap water pipe network monitoring, urban street light control, industrial automation, air defense alarm control, railway signal monitoring, railway water supply control, oil and gas pipeline network monitoring, GPS positioning, remote meter reading, electronic hoisting scales, automatic target reporting, earthquake observation, fire prevention, and environmental monitoring.

13. Precautions for Use

1. Keep the warranty card safe; it contains important technical parameters for maintenance.
2. During the warranty period, free warranty is provided for product defects, not man-made damage or natural disasters. Do not attempt self-repair; contact Ebyte for assistance.
3. Do not operate the DTU near flammable (e.g., coal mines) or explosive materials (e.g., detonators).
4. Use a stable DC power supply with strong anti-interference, low ripple, sufficient load capacity, and protection features (over-current, over-voltage, lightning).
5. Avoid operating in environments exceeding the DTU's specifications (high/low temperature, humidity, strong electromagnetic fields, dust).
6. Do not operate the DTU continuously in full load transmitting state to prevent transmitter burnout.
7. Connect the DTU's ground wire to the external equipment and power supply ground wires to prevent communication interface damage. Do not plug/unplug the serial port while powered on.
8. When testing, connect a matching antenna or a 50Ω dummy load to prevent transmitter damage. Keep human body at least 2 meters away from the antenna during transmission.
9. Communication distance varies by environment. Reserve a 50% margin for stable communication, considering factors like temperature, humidity, obstacles, and electromagnetic environment.
10. If communication distance is suboptimal, analyze antenna quality and installation method. Contact support@cdebyte.com for help.
11. When selecting a power supply, ensure a 50% current margin and a ripple not exceeding 100mV.
12. Wireless products require an impedance-matched antenna for normal operation. Even short-term tests are crucial. Product damage from improper antenna use is not covered by warranty.

Important Statement

1. Ebyte reserves the right of final interpretation and modification of this manual's content.
2. This manual may be updated without notice due to continuous product improvements. The latest version prevails.
3. To reduce paper usage, this manual primarily prints the Chinese version; the English version is electronic. Download from the official website if needed. Product manuals are provided based on order quantity, not necessarily for every DTU.

Revision History

About Us

Technical Support: support@cdebyte.com

Documents and RF Setting Download Link: www.ebyte.com

Thank you for using Ebyte products! For questions or suggestions, please contact: info@cdebyte.com

Official Hotline: 028-61399028

Web: www.ebyte.com

Address: B5 Mould Park, 199# Xiqu Ave, High-tech District, Sichuan, China

FCC Statement

This device complies with Part 15 of the FCC Rules. Operation is subject to two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: —Reorient or relocate the receiving antenna. —Increase the separation between the equipment and receiver. —Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. —Consult the dealer or an experienced radio/TV technician for help. Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter.