eletechsup N4DIG08 8-Channel I/O UART RS485 Modbus RTU Controller Manual

1. Introduction

This manual provides detailed instructions for the eletechsup N4DIG08 8-channel Input/Output UART RS485 Modbus RTU Controller PLC Expansion board. This versatile module is designed for integration with various microcontrollers such as Arduino UNO, MEGA, NANO, STM32, AVR, and PIC, facilitating digital input and output control via the robust RS485 Modbus RTU protocol. It is suitable for applications in automated industry PLCs, smart home systems, identification systems, CCTV camera PTZ control, security systems, and LED dot matrix screens.

The N4DIG08 module offers flexible configuration with three functional modes: 8-channel input, 8-channel output, or 4-channel input and 4-channel output, selectable via onboard jumpers. It supports a wide operating voltage range and configurable baud rates, making it adaptable to various industrial and hobbyist projects.

2. Specifications

3. Setup and Wiring

3.1 Jumper Configuration for Functional Modes

The N4DIG08 module supports three functional modes, which are selected by configuring the onboard jumpers (M2, M1, M0). Refer to the diagram below for the correct jumper settings for each mode:

• 8 Input Mode: Channels 1-8 are configured as inputs.
• 8 Output Mode: Channels 1-8 are configured as outputs.
• 4 Input/4 Output Mode: Channels 1-4 are inputs, and channels 5-8 are outputs.

3.2 Power Supply Connection

Connect the DC power supply to the VIN and GND terminals. The module operates within a DC 6-25V range, with a typical operating voltage of 12V.

• VIN: Positive terminal of the DC power supply.
• GND: Ground terminal of the DC power supply.

3.3 RS485 Bus Connection

Connect the RS485 bus lines to the A+ and B- terminals on the module. Ensure correct polarity for reliable communication.

• A+: RS485 Data+ line.
• B-: RS485 Data- line.

3.4 Input/Output Wiring Diagrams

3.4.1 8-Channel Input Wiring Diagram

This diagram illustrates the wiring for the 8-channel input mode. Both low-level (default) and high-level input configurations are shown. High-level input requires configuration via a register.

3.4.2 8-Channel Output Wiring Diagram

This diagram shows the wiring for the 8-channel output mode. The default output is PNP Low level. NPN High level output requires configuration via a register. When operating in 8-channel output mode, the jumper must be shorted as indicated in the diagram.

3.4.3 4 Input / 4 Output Wiring Diagram

This diagram details the wiring for the 4 input and 4 output mode. When operating in this mode, the jumper must be shorted as indicated in the diagram.

4. Operating Instructions

4.1 Modbus RTU Communication

The N4DIG08 module communicates using the Modbus RTU protocol, supporting 03, 06, and 16 command modes. It can be integrated into a Modbus network with up to 247 devices, each assigned a unique Slave ID.

You can set different "Slave ID" by command. Refer to the Modbus RTU protocol documentation for detailed command structures and register addresses for reading inputs and controlling outputs.

4.2 Baud Rate Configuration

The default baud rate is 9600 BPS. The module can be configured to support other baud rates including 1200, 2400, 4800, and 19200 BPS. The method for changing the baud rate is typically done via Modbus commands to specific registers. Consult the full Modbus instruction manual (available upon request from the seller) for details on baud rate configuration.

4.3 Input Port Status

The input port status supports both query (default behavior) and automatic reporting. This functionality allows the master device to either poll the module for input states or receive unsolicited updates when an input changes, depending on the configuration.

4.4 High-Level Input/NPN High-Level Output Configuration

For high-level input mode or NPN high-level output mode, specific configuration registers need to be set via Modbus commands. Refer to the detailed Modbus instruction manual for the exact register addresses and values required for these advanced configurations.

5. Maintenance

The N4DIG08 module is designed for robust operation and requires minimal maintenance. Follow these guidelines to ensure longevity:

• Cleaning: Keep the module free from dust and debris. Use a soft, dry cloth for cleaning. Avoid using liquids or abrasive cleaners.
• Environmental Conditions: Operate the module within the specified operating temperature range (-40°C to 85°C). Avoid exposure to excessive moisture, corrosive environments, or strong electromagnetic interference.
• Connections: Periodically check all wiring connections to ensure they are secure and free from corrosion.
• Power Supply: Ensure the power supply voltage remains within the specified DC 6-25V range to prevent damage to the module.

6. Troubleshooting

If you encounter issues with your N4DIG08 module, consider the following troubleshooting steps:

• No Power/Module Not Responding:
  • Verify that the power supply is connected correctly to VIN and GND and is within the DC 6-25V range.
  • Check for any loose connections or damaged wires.
• Communication Errors (RS485):
  • Ensure RS485 A+ and B- lines are connected with correct polarity.
  • Verify that the baud rate configured in your master device matches the module's baud rate (default 9600 BPS).
  • Check for proper termination resistors on the RS485 bus if using long cables or multiple devices.
  • Confirm that each module has a unique Modbus Slave ID.
• Incorrect Input/Output Behavior:
  • Review the jumper settings (M2, M1, M0) to ensure the module is configured for the desired functional mode (8 Input, 8 Output, or 4 Input/4 Output). Refer to Section 3.1.
  • For output issues, ensure the jumper is correctly shorted as per the wiring diagrams for 8-channel output or 4 input/4 output modes.
  • Check the wiring for inputs and outputs against the respective diagrams in Section 3.4.
  • If using high-level input or NPN high-level output, confirm that the necessary configuration registers have been set via Modbus commands.
• Module Overheating:
  • Ensure the module is not overloaded beyond its specified current limits.
  • Provide adequate ventilation if operating in an enclosed space.

If the problem persists after these steps, please contact the seller for further assistance.

7. User Tips

• Documentation: While this manual provides essential information, for advanced Modbus programming and register details, it is recommended to request the full "N4DIG08 MODBUS RTU instruction" manual from the seller after purchase.
• Wiring Verification: Always double-check your wiring against the provided diagrams before applying power to prevent damage to the module or connected devices.
• Slave ID Management: When using multiple N4DIG08 modules on the same RS485 bus, ensure each module is assigned a unique Slave ID to avoid communication conflicts.
• Compatibility: The module is compatible with a wide range of microcontrollers. Ensure your chosen microcontroller's UART and Modbus library are correctly configured to interface with the N4DIG08.

8. Warranty and Support

For warranty information and technical support, please refer to the seller's policies or contact the eletechsup customer service directly. Keep your purchase records handy for any warranty claims.