1 Product Overview

DAQ-GP-CT485 split core current transformer is a kind of current sensor (transformer) which can convert AC analog signal into RS485 digital signal launched by Shanghai Data Acquisition IOT Technology Co., LTD. The product has built-in 32-bit ARM series MCU and high-precision metering chip, and is a multi-point calibrated current conversion module. It has the characteristics of high precision and fast response. DAQ-GP-CT485 can directly interact with common data acquisition gateways, DTU, programmable controller PLC, and host computer.

This product is widely used in AC motor, lighting equipment, air compressor, heating ventilation and air conditioning equipment, building self-control system, equipment OEE open rate, industrial Internet, rural power transformation projects and other scenarios of current monitoring and acquisition scenarios.

2 Service Concept

Our company solemnly promise you:

You buy more than just products, but also meticulous and thoughtful technical support. 

We provide free remote guidance, remote configuration and commissioning services, and send data to the server specified by the customer.

Free IOT solution consulting services!

3 Product Characteristic Parameters

Line Sequence Definition

Red:+12V   Black：GND  Yellow：485A  White：485B

Length of Line：Default 1 meter

Acquisition Characteristic

l Current detection range:  AC 0.2A-100A，Other large range transformers can be customized

Electrical Characteristic

l Power supply mode：5~24V DC

l Operating power consumption：0.5W

l Operating frequency：50-60Hz

Communication Characteristic

l Transmission mode：RS485 

l Communication protocol:  Modbus RTU

Structural Characteristic

l Material：ABS plastic (enclosure)

l Installation method：Buckle mounting

Working Environment

l Temperature: -20°C～70°C

Storage Environment

l Temperature: -20°C～80°C

4 The Core Advantages of the Product

Ø High precision measuring chip, high measurement accuracy

Ø Open type design, easy to install

Ø Easy installation and fast deployment, helping IOT projects land quickly

5 Description of the Modbus Communication Protocol

5.1 Serial Port Communication Parameters

Baud rate：9600      Data bit：8      Verify：NONE      Stop bit：1

5.2 Function Code Definition

The upper computer uses 03 function code to read data or receive alarm data.

The host computer controls the lower machine equipment (transformer) using 06 function code.

5.3 Register Point Table Definition

Register table：

5.4 Communication Packet Examples

Give an example：

Host reads the sensor value：

Return data from slave：

The register value is 0x00002710, and the decimal notation is 10000. Assuming that the AC transformer ranges from 0 to 100A, the current is 100A.

Changing a device address：（0x01 is changed to 0x02）

Host sending：

Return data from slave：

The new address takes effect only after the current device address is returned from the slave.

Modified baud rate：(9600 is changed to 1200)

Host sending：

Return data from slave：

（Note: The baud rate takes effect only after the device is powered on again. Change back to 9600 host and send 01 06 00 04 00 05 08 08）

Baud rate register (0x04) Value description：

6 Application Cases

Collection of current data of production equipment in textile factory

In this case, 4G wireless open-type AC sensor is used to collect current data, and the data is displayed on the cloud platform. The data can be accessed and viewed through websites, apps, WeChat mini programs, etc.