EBYTE 433L37 Wireless Modem
Introduction
Brief Introduction
E32-DTU (433L37) is a wireless data transceiver of 433M with standard RS232/RS485 connectors. They are half-duplex. TX & RX modems with LoRa technology and transparent transmission mode. Voltage supply ranges from 8V to 28V, Working frequency: 425~450.5MHz (Default:433MHz).
The LoRa direct sequence spread spectrum technology enables a longer communication distance and better power density concentration as well as superior anti-interference ability. The FEC algorism enables higher coding efficiency and correction ability. The interfered data packets will be corrected proactively upon sudden interference, which significantly improves reliability and communication distance. Without FEC, the interfered data packet will be dropped. The transceivers feature data encryption and compression. The data transmitted in air features randomness, the rigorous algorism makes data interception meaningless. The data compression function has the possibility to reduce the data transmission time, which in turn reduces the possibility of being interfered with, thus improving the reliability and communication efficiency
Features
- All core components are originally imported, our transceiver modems have many advanced functions with smaller sizes and lower costs.
- The top TX power is 5W, all technical parameters meet European industrial standards.
- Temperature compensators are adopted to make the frequency stability better than ±1.5PPM.
- Operation temperature range: -40℃ ～ +85℃, applicable for various harsh environments, it is real industrial-grade products.
- Aluminum alloy case, compact size, great heat dispersion; good shielding, prime electromagnetic compatibility, and strong anti-interference.
- Power reverse & overload protection and antenna surge protection functions significantly improve the reliability.
- Parameters can be configured by programming, such as TX power, frequency point, air data rate, address, and so on.
- Ultra-low power consumption, standby current is only 44mA (even lower under power-saving and sleep modes), TX current ≤1.0A.
- Embedded watch-dog and precise time layout, the modem will restart automatically upon the abnormal situation and work with previous parameters.
- The transceivers adopt the original SEMTECH SX1278 chip, customers highly commend the products because of the super reliability
Operation
Main parts
- First step is to mount the antenna, then the battery, making sure the dial switch is on its right status. The user gets on the power by choosing either VCC/GND or power adapter.
- Using USB-(RS232) converter or USB-RS(485) converter or other way to link computer and DTU.
- Firing up two XCOMs, choosing Baud rate 9600bps, 8N1, the setting which serial port transmission can be achieved.
- User needs to open the mode switch first before linking DTU with the computer if the user wants to modify parameters. Firing up E32-DTU parameter configuration application) to modify related parameters. The mode switch must be reopened to achieve transmission after the configuration
Installation Specifications
Structure
| Pin NO. | Name | Function | Description |
| 1 | DB-9 female socket | RS-232 interface | Standard RS-232 interface |
| 2 | 3.81 terminal block | RS-485, power interface | Standard RS-485 interface and pressure line power interface |
| 3 | PWR-LED | Power LED | Red, lit when the power is on |
| 4 | TXD-LED | Transmit LED | Yellow, blinks when sending data |
| 5 | RXD-LED | Receive LED | Yellow, blinks when receiving data |
| 6 | DC power interface | Power interface | In-line round hole, outer diameter 5.5mm, diameter 2.5mm |
| 7 | DIP switch | DIP switch | Controlled by working mode |
| 8 | Antenna interface | SMA-K interface | external thread, 10mm, 50Ωcharacteristic impedance |
Dimension
Interface Definition
Power interface definition
Users can choose ⑥ DC power interface, using the power adapter supply with the interface of the 5.5mm outer diameter, 2.5mm diameter ;
Also choose the VCC and GND terminal power supply, only choosing any one of the power supplies is OK; E32-DTU can use 8~ 28V DC power supply, but it is recommended to use a 12V or 24V DC power supply.
RS232 Interface definition
The E32-DTU can be connected to the device via RS-232 using the standard DB-9 interface.
RS485 Interface definition
E32-DTU can connect the 485_A terminal and 485_B terminal with the device RS-485 A terminal and B terminal
| Pin NO. | Definition | Function | Description |
| 1 | VCC | Crimping power interface, positive | 8 ~ 28V DC, recommended 12V or 24V |
| 2 | GND | Crimping power interface, negative | The power supply negative pole is connected to the system ground and the housing |
| 3 | 485_B | RS-485 interface, interface B | The RS-485 interface B is connected to the device interface B |
| 4 | 485_A | RS-485 interface, interface A | The RS-485 interface A is connected to the device interface A |
Note: The transceiver will be in poor communication when connected to multiple devices , it is recommended to be connected to a single device, please try to use parallel 120Ω resistor between 485_A terminal and 485_B
Technical indicators
Model specifications
| Model | Frequency | Transmit power | Distance | Specifications | Application |
| Hz | W | km | |||
| E32-DTU (433L37) | 433 | 5 | 20 | Strong penetration，anti – interference | To the environment with small data, longdistance, many obstacles |
Note: Test condition: in clear and open air without shelters, 12V /2A power supply, 5dBi gain sucker antenna over 2 meters height from the ground, with the factory default parameters.
General specification parameters
| NO. | Model | Specification | Description |
| 1 | Size（H*W*D） | 124 * 105 * 25 mm | See more at 3.2 Dimension |
| 2 | Weight | 240g | Tolerance: 9g |
| 3 | Temperature | -40℃～85℃ | Meet industrial level |
| 4 | Antenna impedance | 50 Ω | Standard 50 Ω characteristic impedance |
| 5 | Supply voltage | +8 ~ +28V DC | It is recommended to use 12V or 24V |
| 6 | Communication interface | RS232/RS485 | Standard DB9 hole / 3.81 terminal block |
| 7 | Baud rate | Default 9600 | from 1200 to 115200 bps |
| 8 | Address | Default 0 | 65536 configurable addresses |
Frequency range and channels
| Model | Default frequency | Frequency range | Channel spacing | Channels |
| Hz | Hz | Hz | ||
| E32-DTU (433L37) | 433 | 425~450.5 | 0.1 | 32，half duplex |
Note: In the same area when multiple data transceivers are communicating one to one at the same time, it is recommended to set the channel spacing between each group of data transceivers at 2MHz or more.
Transmit power level
| Model | 135mW | 250mW | 500mW | 1w |
| E32-DTU (433L37) | √ | √ | √ | √ |
Note: The lower the transmit power, the closer the transmission distance, but the working current won’t be declined in exact proportion, it is recommended to use the maximum transmit power.
Air data rate
| Model | Default air data rate | Levels | Air data rate(bps) |
| bps | bps | ||
| E32-DTU (433L37) | 2.4 | 6 | 0.3、1.2、2.4、4.8、9.6、19.2 |
Note: The higher the air data rate, the faster the transmission rate, the transmission distance is also closer; when the rate meets the requirements, the lower air data rate, the better quality.
Current parameters
| Model | Transmitting current mA | Standby current mA | ||
| 12V | 24V | 12V | 24V | |
| E32-DTU (433L37) | 1050 | 540 | 44 | 36 |
Note: It is recommended to retain more than 50% of the current margin when selecting the power supply, which will help the data transceiver to work steadily for a long time
Transceiver Length and Sub-packing Mode
| Model | Buffer | Sub-package |
| E32-DTU (433L37) | 512Byte | Automatically send 58 bytes per package |
Note:
- When the receiving data is more than a single packet capacity, the beyond part will be automatically assigned to the second transmission until it is completed;
- The data transceiver can not receive data that is more than the buffer capacity;
Operating mode
E32-DTU (433L37) has four operating modes, if low power consumption is not required, normal communication is recommended to configure the data transceiver for the normal mode (mode 0);
The factory default is normal mode (mode 0).
| Categories | M1 | M0 | Description | |
| Mode 0 | Normal Mode | ON | ON | Open UART and RF，transparent transmission is on |
| Mode 1 | Wake-up Mode | ON | OFF | Air wake-up mode, the packet comes with a wake-up code, |
| Mode 2 | Power-saving Mode | OFF | ON | The air wake-up receive mode, saving receive power, the mode can not be transmitted |
| Mode 3 | Sleep Mode | OFF | OFF | Parameter setting using the configuration software |
Note: no need to care about the wake-up mode (mode 1) and power-saving mode (mode 2) if it doesn’t request low power consumption
Connection diagram when programming
diagrammatic drawing
| Mode | M1 | M0 | Description | |
| Mode 3 | Sleep Mode | Off | Off | Only be programmed using the configuration software in the current mode |
Note:
- programming can only be carried on in a specific mode(see above), if fails, please confirm the work
- If there’s no complicated programming, opening the E32-DTU 数传电台配置软件(E32-DTU parameter configuration application) to modify parameters
Parameter setting instruction
| Parameter | Description |
| Baud rate | The serial port baud rate of a wireless data station at work， is 1200bps～115200bps。 |
| Odd-even check | Support 8N1:no check ；8E1:even-check；8O1:odd-check；Both are 8-bit data bits and 1-bit stop bits. |
| Air data rate （bps） | Wireless communication rate, also known as air baud rate air rate high, data transmission speed, transmission of the same data time delay is small, but the transmission distance will become shorter. |
| Transmitting power | In order to ensure the working efficiency, it is recommended to use the maximum power. If the transmitted power is reduced, the communication distance will become shorter and the required current will be reduced |
| FEC | The lost or interfered data can be partially corrected by complex encoding, which can improve the equivalent receiving sensitivity by about 3dBm. Turning off this function can reduce the communication delay. |
| Transmission mode | Transparent transmission, and send-as-received fixed points: data is sent at fixed points according to the format |
| Wake Up Time | There is no direct relationship with the communication delay. If the customer needs low-power applications, this option shall be adjusted as required. In the power-saving mode, the longer the wake-up time, the lower the power consumption of the receiving end, and the greater the communication delay. |
| IO driven | By default, select the internal TTL signal drive mode。 |
| Station Address | Internal address of wireless data station, stations with the same address as those independent of Modbus address can communicate with each other. This feature can be used to realize software filtering grouping input range :0~65535, decimal number. |
LoRa/ZigBee/WiFi/蓝牙模块-数传电台-无线遥控开关-串口服务器-无线通信模块-成都亿佰特电子科技有限公司
