NOYITO Voltage to Current Module (0-2.5V to 4-20mA) Instruction Manual

1. Introduction

The NOYITO Voltage to Current Module is designed to convert a standard voltage signal (0-2.5V) into a standard current signal (4-20mA). This module utilizes single-chip embedded technology to provide a linear output, making it suitable for direct connection to AD converters or microcontrollers with AD functionality. It is an essential component for applications requiring signal conversion, such as valve adjustment, inverter control, PLC debugging, instrumentation testing, and LED testing.

2. Features

• Converts 0-2.5V voltage signal to 4-20mA current signal.
• Linear output for direct connection to AD converters and microcontrollers.
• Integrated single-chip embedded technology for compact design.
• Adjustable output current via potentiometer for fine-tuning.
• Module operating voltage: DC 12-24V.

3. Specifications

4. Pin Description and Layout

Understanding the pin assignments is crucial for correct wiring and operation of the module.

Figure 1: Module Pinout with Input/Output and Power Connections.

• 24V: Operating power supply positive (DC 12-24V).
• GND: Operating power supply negative (DC 0V).
• VIN+ (V+ / P2): Input voltage positive (0-2.5V DC). Also serves as one end for external potentiometer connection (P2).
• VIN- (V- / P3): Input voltage negative (0V DC). Also serves as the other end for external potentiometer connection (P3).
• P1: Wiper connection for external potentiometer.
• AOUT+: Output current positive (4-20mA).
• AOUT-: Output current negative (0V).

The module also features adjustable potentiometers for calibration:

Figure 2: Module with Potentiometer Labels (VR1 for Span/20mA Full-scale, VR2 for Zero/4mA).

• VR2 (Zero/4mA Potentiometer): Used to adjust the 4mA output corresponding to the minimum input voltage.
• VR1 (Span/20mA Full-scale Potentiometer): Used to adjust the 20mA output corresponding to the maximum input voltage.

5. Setup and Wiring

Proper wiring is essential for the safe and correct operation of the module. Refer to the diagrams below for connection details.

Figure 3: Wiring diagrams for Voltage to Current conversion and Potentiometer to Current conversion.

5.1. Voltage to Current Wiring

1. Connect the Positive (+) terminal of your DC 12-24V power supply to the 24V pin on the module.
2. Connect the Negative (-) terminal of your DC 12-24V power supply to the GND pin on the module.
3. Connect the Positive (+) terminal of your 0-2.5V input voltage source to the VIN+ pin on the module.
4. Connect the Negative (-) terminal of your 0-2.5V input voltage source to the VIN- pin on the module.
5. Connect the Positive (+) terminal of your 4-20mA load (e.g., AD converter, PLC input) to the AOUT+ pin on the module.
6. Connect the Negative (-) terminal of your 4-20mA load to the AOUT- pin on the module.

Important Safety Note: Ensure the working voltage is connected correctly to V+ and V-. Reversing the polarity can damage the control panel and components.

5.2. Potentiometer to Current Wiring (Alternative Input)

This module can also be used with an external potentiometer to generate a current signal. Refer to the "Potentiometer to Current Wiring Diagram" in Figure 3.

1. Connect the Positive (+) terminal of your DC 12-24V power supply to the 24V pin on the module.
2. Connect the Negative (-) terminal of your DC 12-24V power supply to the GND pin on the module.
3. Connect one end of the external potentiometer to the P2 (VIN+) pin.
4. Connect the wiper (middle pin) of the external potentiometer to the P1 pin.
5. Connect the other end of the external potentiometer to the P3 (VIN-) pin.
6. Connect the Positive (+) terminal of your 4-20mA load to the AOUT+ pin on the module.
7. Connect the Negative (-) terminal of your 4-20mA load to the AOUT- pin on the module.

6. Operating Instructions and Calibration

After wiring the module, it may require calibration to ensure accurate 4-20mA output corresponding to the 0-2.5V input range.

1. Initial Power-Up: Apply the DC 12-24V operating voltage to the module.
2. Zero Point (4mA) Adjustment:
   • Apply the minimum input voltage (0V) to the VIN+ and VIN- terminals.
   • Measure the output current at AOUT+ and AOUT-.
   • Adjust the VR2 (Zero/4mA Potentiometer) until the output current reads 4mA.
3. Full-Scale (20mA) Adjustment:
   • Apply the maximum input voltage (2.5V) to the VIN+ and VIN- terminals.
   • Measure the output current at AOUT+ and AOUT-.
   • Adjust the VR1 (Span/20mA Full-scale Potentiometer) until the output current reads 20mA.
4. Verification: Repeat steps 2 and 3 a few times, as adjusting one potentiometer might slightly affect the other setting. Fine-tune until both 0V input yields 4mA output and 2.5V input yields 20mA output accurately.

Once calibrated, the module will linearly convert any voltage within the 0-2.5V range to a corresponding current within the 4-20mA range.

7. Maintenance

The NOYITO Voltage to Current Module is designed for reliable operation with minimal maintenance. Follow these guidelines to ensure longevity:

• Keep Clean: Periodically clean the module with a soft, dry cloth to remove dust and debris. Avoid using liquids or harsh chemicals.
• Environmental Conditions: Operate the module within its specified temperature and humidity ranges. Avoid extreme temperatures, high humidity, or corrosive environments.
• Secure Connections: Ensure all wiring connections are secure and free from corrosion. Loose connections can lead to intermittent operation or damage.
• Power Supply: Use a stable and regulated DC 12-24V power supply to prevent voltage fluctuations that could affect performance or damage the module.

8. Troubleshooting

If you encounter issues with your NOYITO Voltage to Current Module, consider the following troubleshooting steps:

• No Output Current:
  • Verify that the DC 12-24V operating voltage is correctly applied to the 24V and GND terminals.
  • Check all wiring connections for continuity and correct polarity.
  • Ensure the input voltage (0-2.5V) is present at the VIN+ and VIN- terminals.
  • Confirm that the load connected to AOUT+ and AOUT- is functioning correctly and not open-circuited.
• Incorrect Output Current:
  • Perform the calibration procedure described in Section 6 to adjust the Zero (4mA) and Span (20mA) potentiometers.
  • Verify the accuracy of your input voltage source and current measurement device.
  • Ensure the input voltage is within the 0-2.5V range. Voltages outside this range will not produce a linear 4-20mA output.
• Module Not Powering On:
  • Check the power supply voltage and ensure it is within the 12-24V DC range.
  • Confirm that the power supply polarity is correct (24V to 24V, GND to GND). Reversed polarity can damage the module.

9. Warranty and Support

NOYITO brand products come with a two-year after-sales warranty. If there is a non-human product failure within two years of purchase, please contact NOYITO customer service for after-sales support. This warranty covers manufacturing defects and ensures product reliability under normal operating conditions.

For technical assistance or warranty claims, please refer to the contact information provided with your purchase or visit the official NOYITO support channels.