1. Introduction
This manual provides comprehensive instructions for the eletechsup 8-24 Channel 4-20MA Current & 0-30V Voltage Input RS485 AI Module series (N4AIA08, N4AIB16, N4AIC24). These modules function as 12-bit ADC Collector Boards utilizing MODBUS RTU protocol for PLC IO applications. They are designed for acquiring analog current and voltage signals, suitable for various industrial and home automation systems.
2. Specifications
| Feature | Description |
|---|---|
| Product Type | Relay, Analog Input Collector Module |
| Working Voltage | DC 7-25V (typically DC 12V/24V) |
| Working Current | Standby: 6-8mA, Operating: 10-30mA |
| Protocol | Standard Modbus RTU (Function codes: Write 06/16, Read 03/04) |
| Protection Features | Hardware reset, RS485 with TVS anti-surge, anti-reverse power supply, self-recovery fuse |
| Parallel Devices | Up to 64 devices in Modbus command mode |
| Baud Rate | Default 9600BPS (Selectable: 1200, 2400, 4800, 19200, 38400, 57600, 115200BPS) |
| Check Mode | No check, Even check, Odd check |
| Data Return Time | Configurable, maximum 1000ms |
| Maximum Load | 10A/250VAC, 10A/125VAC, 10A/30VDC, 10A/28VDC, 10A/12VDC |
| Origin | Mainland China |
Model-Specific Details:
| Model | Channels | Dimensions (Board) | Dimensions (With Box) | Weight (Board) | Weight (With Box) |
|---|---|---|---|---|---|
| N4AIA08 | 8-channel 0-20mA/4-20mA acquisition | 47 x 72 x 12mm | 49 x 82 x 40mm | 33 grams | 77 grams |
| N4AIB16 | 15-channel 0-20mA/4-20mA acquisition, 1-channel 0-30V voltage acquisition | 77 x 72 x 12mm | 79 x 82 x 40mm | 54 grams | 116 grams |
| N4AIC24 | 22-channel 0-20mA/4-20mA acquisition, 2-channel 0-30V voltage acquisition | 99 x 72 x 12mm | 101 x 82 x 40mm | 70 grams | 146 grams |
3. Safety & Warnings
Please read all instructions carefully before using the product. Failure to follow these instructions may result in product damage or personal injury.
- Keep the device and its cord out of reach of children under 3 years old.
- Keep away from children unless supervised by an adult.
- Do not use this product for purposes other than its intended use.
- Inspect the product before each use; do not use if damaged.
- Follow all installation and operation guidelines to avoid injury.
- Do not expose the module to water or moisture.
- Handle with care to avoid cuts or injuries, especially when working with exposed circuit boards.
4. Setup and Wiring
4.1 Interface Definition
- VIN: Power input +
- GND: Power input -
- I1 to I22: Current input channels (e.g., I1 for channel 1, I22 for channel 22)
- V1+ to V2+: Voltage input channels (e.g., V1+ for channel 1, V2+ for channel 2)
- A+: RS485 signal A+
- B-: RS485 signal B-
4.2 Wiring Diagrams
4.3 Model Channel Configurations
5. Operating Instructions
5.1 Initial Use
- Before first use, remove all protective films from the device.
- Ensure all wiring is correctly connected according to the diagrams in Section 4.
- Apply DC 7-25V power to the VIN and GND terminals.
5.2 Modbus RTU Communication
The module supports standard Modbus RTU commands. Use function codes 03/04 for reading data and 06/16 for writing data. The default baud rate is 9600BPS, but it can be configured via commands to 1200, 2400, 4800, 19200, 38400, 57600, or 115200BPS. You can also select the check mode (no check, even check, or odd check) and set the data sending return time up to 1000ms.
5.3 Restoring Factory Settings
To restore the module to its factory default settings, short-circuit the 'RES' pad for 5 seconds, then power on the module again. Refer to Figure 1 for the location of the 'RES' pad.
5.4 After Use
- Turn off the device when not in use.
- Store it in a dry place, away from children.
6. Maintenance
- Regularly inspect the module for any signs of damage, loose connections, or corrosion. Do not use if damaged.
- Keep the module clean and free from dust and debris. Use a soft, dry cloth for cleaning.
- Ensure the operating environment is within specified temperature and humidity ranges to prevent damage.
- Store the module in a dry, cool place when not in use.
7. Troubleshooting
- No Power: Check the DC 7-25V power supply connections (VIN, GND) and ensure the power source is active. Verify the self-recovery fuse is not tripped.
- No Communication: Verify RS485 A+ and B- connections. Check baud rate, parity, and stop bit settings on both the module and the master device. Ensure the module address is unique if multiple devices are on the bus.
- Incorrect Readings: Check sensor wiring (three-wire vs. two-wire, refer to Figure 2). Ensure the sensor type (4-20mA or 0-30V) matches the module's input configuration. Calibrate sensors if necessary.
- Module Unresponsive: Try restoring factory settings by short-circuiting the 'RES' pad for 5 seconds and then powering on again.
8. User Tips
No specific user tips were available from reviews or Q&A for this product.
9. Frequently Asked Questions (FAQ)
No specific FAQ content was available from Q&A data for this product.
10. Warranty and Support
For detailed technical information, programming guides, and further support, please refer to the official documentation. A user manual PDF is available for download:
For direct support, you may contact the manufacturer:
- Manufacturer: Guangzhou Keshen Electronic Technology Co., Ltd
- Email: eletechsup@163.com
