USB to Current Output Interface (4-20mA, 0-20mA)

With 24V Loop Power Supply

(Similar Product: ADU72 USB to Current Input Interface)

ADU71 USB to 0-20mA, 4-20mA Current Loop Output Interface


The ADU71 USB to Current Output Interface (Transmitter) is a USB bus powered current loop source for driving 4-20mA or 0-20mA input devices. The ADU71 can also be used with external resistors to provide 1-5VDC, 0-5VDC or 0-10VDC signals for variable frequency drives, valves etc. The ADU71 internally generated 24VDC loop supply eliminates the need for an external loop power supply. This low-cost USB to Current Output Interface is easy to use with VB, VB.NET, Visual C++, C , MATLAB, LABView etc. via standard HID drivers included with Windows. A mini-driver (DLL) is also provided allowing control using standard ASCII commands using familiar readfile, writefile commands. The ADU71 includes a 10' USB cable and is available in a flange mount enclosure with a DIN rail mount option.

Click here to view sample connection diagrams.

Download the ADU 71 Operating Commands

Download the ADU 71 User Manual

Download ADU71 3D STEP files for FLANGE or DIN  mounting types.

Key Features

Technical Specification

ADU71 Features
Supply Voltage NONE (Bus Powered)
USB Supply Current 70mA Typical 100mA Max ( 24V loop supply disabled)
180mA Typical 200mA Max ( 24V loop supply enabled)
Operating Temperature -25C Min to 85C Max
Isolation 2500V
Current Loop Output
Resolution 16 Bits
Range 0-20mA or 4-20mA programmable
Total Unadjusted Error -0.3%FSR MIN  +0.3% FSR MAX
Full Scale Error -0.2% FSR MIN  +0.2% FSR MAX
Temperature Stability +/- 16 ppm /Degree C
Slew Rate 1ms to 10s programmable
Internal Loop Power Supply
Voltage 24 Volts Nominal
Isolation 2500V
Loop Compliance Voltage 21VDC
Special Functions
Internal Loop Power Supply 24VDC
Mounting Options Flange Mount (STANDARD), DIN Rail


ADU71 Qty 1-4


ADU71 Qty 5-9


ADU71 Qty 10+


IMPORTANT: Specify mounting option when ordering.-FLANGE(standard) or -DIN . See Mounting Options for details.

Mounting Options

ADU71 USB 4-20mA Current Input Module FLANGE Mount
Comes standard with ADU71.
ADU71 USB 4-20mA Current Input Module DIN Mount
A $5 surcharge applies to the DIN RAIL option.