20 Channel AC/DC Current Acquisition Module with RS485 Modbus-RTU

Product Overview

The 20-channel through-hole AC/DC current acquisition module is designed for real-time multi-channel current monitoring and industrial data acquisition applications. The module integrates high-precision closed-loop current sensors and true RMS measurement technology, enabling accurate acquisition of AC and DC current signals, including distorted waveforms.

The device supports simultaneous sampling of 20 independent current channels and optional total voltage measurement. With isolated RS485 communication and standard Modbus-RTU protocol, it is widely used in industrial automation, aging test systems, production line monitoring, electrical equipment testing, and power management systems.

The module adopts industrial-grade 24-bit high-precision ADC sampling with excellent linearity, temperature stability, and long-term reliability.

Main Features

1.20-channel simultaneous independent A/D sampling

2.Fast acquisition update rate up to 20ms
3.High-precision closed-loop current sensor
4.Linear error less than 0.2%
5.True RMS measurement for AC/DC signals
6.Supports distorted waveform measurement
7.RS485 communication with Modbus-RTU protocol
8.Optional hardware DIP switch or software configuration
9.Isolated voltage input measurement
10.Full isolation between input, power supply, and communication
11.Isolation withstand voltage >2500V DC
12.Supports absolute value and bipolar measurement modes
13.Industrial DIN rail mounting
14.No exposed electrical solder pads on the front panel for improved EMC performance

Product Model

ZH-44102A-14F5:10-channel through-hole DC current acquisition module

ZH-44202A-14F5:20-channel through-hole DC current acquisition module

ZH-44103A-14F5:1 voltage input + 10-channel current acquisition module

ZH-44203A-14F5:1 voltage input + 20-channel current acquisition module

Technical Specifications

Current Measurement

Parameter	Specification
Accuracy	0.5% FS
Current Range	5A / 10A / 20A / 30A / 40A
Measurement Type	AC/DC Universal Measurement
Current Hole Diameter	8.5mm
Sensor Type	Closed-loop current sensor
ADC Resolution	24-bit

Voltage Measurement

Parameter	Specification
Voltage Range	30V / 60V / 100V / 300V / 400V
Measurement Type	AC/DC Universal Measurement
Input Impedance	10kΩ/V (<100V range),2kΩ/V (>100V range)

Communication Interface

Parameter	Specification
Interface	RS485
Protocol	Modbus-RTU
Baud Rate	2400 / 4800 / 9600 / 19200 / 38400 / 57600 / 115200 bps
Data Format	8 Data Bits, 1 Stop Bit
Parity	None / Odd / Even

Default factory communication settings:

1.Address: 1

2.Baud Rate: 9600bps

3.Parity: None

4.Data Bits: 8

5.Stop Bit: 1

Electrical Characteristics

Parameter	Specification
Isolation Voltage	>2500V DC
Auxiliary Power Supply	10V ~ 30V DC
Power Consumption	<4W
Typical Current Consumption	<160mA @24V
Operating Temperature	-40℃ ~ +85℃

Sampling Update Rate

Configurable data refresh interval:20ms/40ms/60ms/80ms/100ms (default)/400ms/1000ms

Installation

1.Standard 35mm DIN rail mounting
2.Compact industrial design
3.Suitable for electrical cabinets and automation systems

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Typical Applications

1.Industrial automation systems
2.Aging test equipment
3.Production line monitoring
4.PLC current monitoring
5.Multi-channel power monitoring
6.Electrical laboratory testing
7.Industrial IoT data acquisition
8.Motor current monitoring
9.Energy management systems
10.Factory equipment diagnostics
Advantages for Industrial Applications

Compared with traditional current monitoring devices, this module provides:

1.Multi-channel centralized acquisition

2.Faster response speed

3.Higher isolation safety

4.Better anti-interference performance

5.Accurate true RMS measurement

6.Long-term stability without zero drift

7.Easy PLC and SCADA integration via Modbus-RTU

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Customization Support

Customized services are available:

1.Current range customization

2.Voltage range customization

3.Private label service

FAQ – 20 Channel AC/DC Current Acquisition Module

1. What communication protocol does this current acquisition module support?

The module supports standard RS485 communication with Modbus-RTU protocol, making it compatible with PLCs, SCADA systems, industrial PCs, and various industrial automation controllers.

2. Can this module measure both AC and DC current?

Yes. The module supports universal AC/DC current measurement and uses true RMS measurement technology to accurately measure sinusoidal and distorted waveforms.

3. How many current channels can be monitored simultaneously?

This model supports simultaneous acquisition of 20 independent current channels. Each channel is independently sampled for high accuracy and fast response.

4. Does the module support voltage measurement?

Yes. Selected models support 1 channel total voltage measurement in addition to 20 current channels.

5. What current ranges are available?

Available current measurement ranges include:5A-60A DC

Custom ranges may also be available upon request.

6. What is the accuracy of the current measurement?

The module provides 0.5% FS measurement accuracy with linear error less than 0.2%.

7. What is true RMS measurement?

True RMS measurement allows the module to accurately measure non-sinusoidal and distorted waveforms, which is important in industrial automation and variable frequency drive applications.

8. Is the module electrically isolated?

Yes. Input signals, power supply, and communication interfaces are fully isolated with isolation withstand voltage greater than 2500V DC.

9. What is the sampling speed?

The fastest data acquisition update rate is 20ms for all 20 channels. Multiple refresh intervals are configurable depending on application requirements.

10. What baud rates are supported?

Supported baud rates include:2400bps/4800bps/9600bps/19200bps/38400bps/57600bps/115200bps

11. What are the default communication settings?

Factory default settings are:Address: 1,Baud Rate: 9600bps,Parity: None,Data Bits: 8,Stop Bit: 1

12. How is the module installed?

The module supports standard 35mm DIN rail mounting for industrial control cabinets and automation systems.

13. What applications is this module suitable for?

Typical applications include:

1.Industrial automation

2.Aging test systems

3.Power monitoring

4.Production line testing

5.Equipment diagnostics

6.Motor current monitoring

7.Industrial IoT systems

8.PLC data acquisition

14. Does the module support distorted waveform measurement?

Yes. The built-in true RMS measurement chip can accurately measure distorted waveforms and non-linear loads.

15. Can multiple modules be connected on the same RS485 bus?

Yes. Up to 255 devices can be connected on the same RS485 Modbus network.

16. What operating temperature range does the module support?

The module operates reliably within:

-40°C to +85°C

making it suitable for harsh industrial environments.

17. What power supply is required?

The module requires a DC auxiliary power supply between 10V and 30V.

18. Is OEM or ODM customization available?

Yes. We support OEM/ODM customization including:

1.Current range customization

2.Voltage range customization

3.Communication parameter customization

4.Label and branding customization

19. What type of current sensor is used?

The module uses high-precision closed-loop current sensors with excellent linearity, low temperature drift, and long-term stability.

20. Does the module support PLC integration?

Yes. The module is widely used with Siemens, Mitsubishi, Delta, Omron, Schneider, and other PLC systems via Modbus-RTU communication.