How to Use Waveshare industrial 8-ch (b) analog acquisition module with default voltage mode (0—10v): Examples, Pinouts, and Specs

The Waveshare Industrial 8-CH (B) Analog Acquisition Module is a robust and versatile device designed for industrial applications. It is capable of measuring analog voltages in the range of 0 to 10 volts across 8 independent channels. This module is ideal for scenarios requiring simultaneous data acquisition from multiple analog sources, such as industrial automation, process monitoring, and control systems.

• Industrial automation systems
• Process monitoring and control
• Data acquisition in laboratory environments
• Sensor signal measurement and logging
• IoT systems requiring multi-channel analog input

The following table outlines the key technical details of the Waveshare Industrial 8-CH (B) Analog Acquisition Module:

The module features a terminal block for power, communication, and analog input connections. Below is the pin configuration:

1. Power Connection: Connect a DC power supply (9–24 V) to the V+ and GND terminals.
2. Analog Input: Connect the analog signal sources (e.g., sensors) to the CH1–CH8 terminals. Ensure the input voltage does not exceed the 0–10 V range.
3. Communication: Connect the A+ and B- terminals to an RS485-compatible device (e.g., PLC, computer with RS485 adapter, or microcontroller).
4. Configuration: Use Modbus RTU commands to configure and read data from the module. Refer to the Modbus register map provided in the manufacturer's documentation.

• Ensure the input voltage for each channel remains within the 0–10 V range to avoid damage to the module.
• Use shielded cables for RS485 communication to minimize noise and interference.
• Terminate the RS485 bus with a 120-ohm resistor at both ends for reliable communication.
• Mount the module securely on a DIN rail or wall to prevent vibration-related issues.
• If using with a microcontroller like Arduino, ensure the RS485 adapter is properly connected and configured.

To interface the module with an Arduino UNO, you will need an RS485-to-TTL adapter. Below is an example Arduino sketch for reading data from the module:

#include <ModbusMaster.h>

// Instantiate ModbusMaster object
ModbusMaster node;

// RS485 communication pins
#define RE_PIN 2  // Receiver Enable pin
#define DE_PIN 3  // Driver Enable pin

void preTransmission() {
  digitalWrite(RE_PIN, HIGH); // Enable RS485 driver
  digitalWrite(DE_PIN, HIGH);
}

void postTransmission() {
  digitalWrite(RE_PIN, LOW);  // Disable RS485 driver
  digitalWrite(DE_PIN, LOW);
}

void setup() {
  // Initialize serial communication
  Serial.begin(9600); // For debugging
  Serial1.begin(9600); // RS485 communication

  // Configure RS485 control pins
  pinMode(RE_PIN, OUTPUT);
  pinMode(DE_PIN, OUTPUT);
  digitalWrite(RE_PIN, LOW);
  digitalWrite(DE_PIN, LOW);

  // Modbus communication setup
  node.begin(1, Serial1); // Set Modbus slave ID to 1
  node.preTransmission(preTransmission);
  node.postTransmission(postTransmission);
}

void loop() {
  uint8_t result;
  uint16_t data[8];

  // Read 8 registers starting from address 0x0000
  result = node.readInputRegisters(0x0000, 8);

  if (result == node.ku8MBSuccess) {
    for (int i = 0; i < 8; i++) {
      data[i] = node.getResponseBuffer(i);
      Serial.print("Channel ");
      Serial.print(i + 1);
      Serial.print(": ");
      Serial.println(data[i] * (10.0 / 4095.0)); // Convert to voltage
    }
  } else {
    Serial.print("Error: ");
    Serial.println(result);
  }

  delay(1000); // Wait 1 second before next read
}

1. No Communication with the Module

   • Verify the RS485 connections (A+ and B-) and ensure they are not swapped.
   • Check the baud rate and Modbus slave ID in your software configuration.
   • Ensure the RS485 bus is properly terminated with 120-ohm resistors.

2. Incorrect Voltage Readings

   • Confirm that the input voltage is within the 0–10 V range.
   • Check for loose or faulty connections on the analog input terminals.
   • Ensure the power supply voltage is stable and within the specified range.

3. Module Not Powering On

   • Verify the power supply voltage is between 9–24 V DC.
   • Check the polarity of the power connections (V+ and GND).

Q: Can this module measure negative voltages?
A: No, the module is designed to measure voltages in the range of 0–10 V only.

Q: What is the maximum cable length for RS485 communication?
A: RS485 supports cable lengths up to 1200 meters, but this may vary depending on baud rate and environmental noise.

Q: Can I use this module with a Raspberry Pi?
A: Yes, you can use an RS485-to-USB or RS485-to-TTL adapter to connect the module to a Raspberry Pi.

Q: Is the module compatible with 4–20 mA sensors?
A: Yes, but you will need a 250-ohm resistor to convert the 4–20 mA current signal to a 1–5 V voltage signal.