1. הקדמה
This manual provides detailed instructions for the Waveshare Industrial Modbus RTU 4-Channel Relay Module. This module is designed for industrial control applications, offering robust RS485 communication, high current switching capabilities, and comprehensive protection features. It is suitable for various scenarios requiring intelligent and automated control.

בילד 1.1: איבערview of the Waveshare Industrial Modbus RTU 4-Channel Relay Module.
2. שליסל פֿעיִקייטן
- Configurable RS485 Communication: Device address is configurable (1~255), allowing multiple devices to be cascaded on the RS485 bus for flexible networking.
- Relay Control with Flash-on/Flash-off: Supports flash-on/flash-off function, enabling relay activation for a specific period before automatically turning off via command arguments.
- ברייט וולtage Range & Isolation: אַנבאָרד וואָלtage regulator supports 7V~36V wide voltage supply, with unibody power supply isolation for stable, isolated voltage without requiring an extra power supply for the isolated terminal.
- אַוואַנסירטע שוץ פֿעיִקייטן: Includes onboard resettable fuse, TVS (Transient Voltage Suppressor), optocoupler isolation, and relay driver chip with flyback diode protection for surge suppression, anti-electrostatic, and high-voltage interference prevention.
- Reliable, Easy Installation: High-quality relay with a contact rating of ≤30A 250V AC or ≤30A 28V DC, housed in a rail-mounted ABS plastic enclosure with 3 LEDs to indicate MCU and signal transceiving status.
- Rich Wiki Resources: Additional resources are available on the official Waveshare Wiki.
3. פּעקל אינהאַלט
דער פּעקל כולל די פאלגענדע זאכן:
- Modbus RTU Relay 4CH x1
Note: The power supply for this product is not included. A 12V power supply is recommended. A USB to RS232/485/TTL or USB to RS485 converter may be useful for testing and communication setup.

Image 3.1: Contents of the product package, showing the Modbus RTU Relay 4CH module.
4. ספּעסאַפאַקיישאַנז
| פּאַראַמעטער | ווערט |
|---|---|
| מאַכט צושטעלן | 7-36וו |
| קאָמוניקאַציע צובינד | RS485 |
| באַודראַטע | 4800, 9600, 19200, 38400, 57600, 115200, 128000, 256000 |
| Default Communication Format | 9600 , ן , 8 , 1 |
| רעלע טשאַנאַלז | 4 |
| קאָנטאַקט פאָרעם | 1NO 1NC (Normally Open, Normally Closed) |
| קאָנטאַקט רייטינג | ≤30A 250V AC or ≤30A 28V DC |
| קאָמוניקאַציע פּראָטאָקאָל | Standard Modbus RTU protocol |
| RS485 אַדרעס | 1-255 (Configurable) |
| געפירט ינדיקאַטאָרס | STA: MCU indicator (keeps flashing when MCU is working normally) TXD: TX indicator (lights up when sending data) RXD: RX indicator (lights up when receiving data) |
| מאַונטינג טיפּ | דין רעלס בארג |
| קאָנטאַקט מאַטעריאַל | זילבער |
| קאַנעקטער טיפּ | שרויף טערמינאַלס |

Image 4.1: Visual representation of the module's features and technical specifications.
5. סעטאַפּ און ייַנמאָנטירונג
5.1 מאַכט סופּפּלי קאַנעקשאַן
Connect a 7V to 36V DC power supply to the designated power input terminals on the module. Ensure correct polarity (+ and -). The module features an onboard voltage regulator and power supply isolation for stable operation.
5.2 RS485 צובינד פֿאַרבינדונג
Connect the RS485 A+ and B- terminals of the module to your RS485 master device (e.g., a computer via a USB to RS485 converter). For multi-device setups, ensure proper cascading and consider using RS485 repeaters for long communication distances.

Image 5.1: Diagram illustrating RS485 communication setup with multiple modules and examples of AC and DC relay connections.
5.3 רעלע רעזולטאַט קאַנעקשאַן
Each of the 4 relay channels provides Normally Open (NO) and Normally Closed (NC) contacts, along with a Common (COM) terminal. Connect your target device (e.g., light, motor, valve) to the appropriate relay contacts based on your control requirements. The high current screw terminals are designed for secure wiring of devices up to 30A.

בילד 5.2: דעטאַלירט view of the high current screw terminals and a hardware analysis showing internal components like optocoupler isolation and TVS protection.
5.4 Rail-Mount Installation
The module is housed in a rail-mounted ABS plastic enclosure, facilitating easy installation and removal on standard DIN rails in industrial control cabinets.

Image 5.3: Illustration of the module's interfaces, LED indicators, and its rail-mount enclosure design.
6. אַפּערייטינג ינסטרוקטיאָנס
6.1 Modbus RTU Communication
The module communicates using the standard Modbus RTU protocol over the RS485 interface. You can send Modbus commands from a master device to control the relays and read their status. The device address is configurable from 1 to 255.
For detailed Modbus command structures and register maps, refer to the official Waveshare Wiki resources.
6.2 רעלע קאָנטראָל
Relays can be controlled individually or in groups using Modbus commands. The module supports standard ON/OFF commands. Additionally, a flash-on/flash-off function allows a relay to be activated for a specified duration before automatically deactivating.
6.3 געפירט ינדיקאַטאָרס
- STA (Status) LED: Flashes continuously when the Microcontroller Unit (MCU) is operating normally.
- TXD (Transmit) LED: Lights up when the module is sending data over RS485.
- RXD (Receive) LED: Lights up when the module is receiving data over RS485.
These indicators provide visual feedback on the module's operational status and communication activity.
6.4 עקסample of Modbus Control
The following video demonstrates the Modbus RTU Relay series, including connection and basic operation using Modbus commands. This can serve as a practical guide for controlling the module.
ווידעא 6.1: אן איבערview of the Waveshare Modbus RTU Relay series, demonstrating various models and their operational principles. This video highlights the features and application scenarios of the relay modules.
7. אַפּפּליקאַטיאָנס
The Waveshare Modbus RTU Relay Module is versatile and can be applied in various fields:
- אינדוסטריעלע קאָנטראָל: Ideal for valve control, pump station control, and unattended industrial control systems.
- סמאַרט היים: Suitable for controlling appliances like air conditioners, access control systems, purifiers, and water heaters.
- קלוגע לאַנדווירטשאַפט: Can be used for controlling door curtain motors, air blowers, and other agricultural equipment.
- Breeding & Farming: Useful for controlling ventilators, lighting, water supply systems, and feeding systems in breeding and farming environments.

בילד 7.1: עקס.amples of diverse applications for the Modbus RTU Relay Module.
8. וישאַלט
The Waveshare Modbus RTU Relay Module is designed for reliable operation with minimal maintenance. To ensure longevity and optimal performance:
- האַלט דעם מאָדול ריין און פריי פון שטויב און דעבריס.
- זיכער מאַכן געהעריקע ווענטילאַציע אויב אינסטאַלירט אין אַ פארמאכטן אָרט.
- Regularly check all wiring connections for tightness and integrity.
- Avoid exposing the module to extreme temperatures or humidity beyond its specified operating conditions.
9. טראָובלעשאָאָטינג
If you encounter issues with your Modbus RTU Relay Module, consider the following troubleshooting steps:
- קיין מאַכט/לעדס אויסגעלאָשן: באַשטעטיקן די מאַכט צושטעלן וואָלtage (7-36V) and ensure correct polarity. Check power connections.
- קאָמוניקאַציע דורכפאַל:
- Check RS485 wiring (A+ to A+, B- to B-).
- Confirm baudrate, data bits, parity, and stop bits settings match between the master device and the module (default: 9600, N, 8, 1).
- Ensure the device address is correctly configured and unique on the bus.
- Check for proper termination resistors on the RS485 bus if applicable (not explicitly mentioned for this module, but good practice for RS485).
- Observe TXD/RXD LEDs for data transmission activity.
- רעליי נישט אַקטיוויִרט:
- Verify the Modbus command sent is correct for the desired relay and action.
- Check the load connected to the relay for proper wiring and functionality.
- Ensure the load current and voltage do not exceed the relay's contact rating (≤30A 250V AC or ≤30A 28V DC).
- מאָדול איבערהיצונג: Ensure adequate ventilation around the module. Reduce load if consistently operating at maximum capacity.
For further assistance, consult the Waveshare Wiki or contact technical support.
10. וואָראַנטי און שטיצן
For detailed warranty information, please refer to the official Waveshare website or the documentation provided with your purchase. Waveshare provides comprehensive resources and support for its products.
- אָנליין רעסורסן: Visit the official Waveshare Wiki for detailed documentation, examples, and software resources. The Wiki is a primary source for technical information.
- טעכניש שטיצן: For specific technical inquiries or issues not covered in this manual or the Wiki, please contact Waveshare customer support through their official channels.