The Yocto-4-20mA-Rx device lets you read via USB the instant value returned by any industrial sensor following the 4-20mA standard, as well as record the measures on its internal flash for later retrieval when connected again by USB. The device can automatically map the current reading to a physical measure by applying a proportional rule. The module features two inputs, to connect two independent sensors.

You can find sensors for all kinds of physical measures using the standard 4-20mA interface. Transmitting the measure using a 4-20mA current loop makes it possible to get a very accurate reading (up to 0.1%), and works even when the sensor is far away from the interface module (several thousands of meters of cable away).

The Yocto-4-20mA-Rx supports 2-wire sensors (powered from the current loop) as well as 3-wire sensors (that require an additional power supply with shared ground) and 4-wire sensors (with an isolated power supply). It can even provide up to 80mA to power 3-wire sensors that do not require too much power. The supply voltage is regulated 23V, isolated from the USB bus but common to both inputs.

This device can be connected directly to an Ethernet network using a YoctoHub-Ethernet, to a WiFi network using a YoctoHub-Wireless-n and to a GSM network using a YoctoHub-GSM.

Yocto-4-20mA-Rx Yocto-4-20mA-Rx

USB cables and enclosures to be ordered separately.

CHF 92.10

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Hardware release:Rev. D
Product ID:RX420MA1
Product name:Yocto-4-20mA-Rx
USB connector:micro-B
Refresh rate:50Hz
Input impedance:100Ω
Protection class, according to IEC 61140:class III
USB isolation, dielectric strength:1kV
Normal operating temperature:5...40░C
Extended operating temperature2:-30...85░C
Supported Operating Systems:Windows (PC + IoT), Linux (Intel + ARM), macOS, Android
Drivers:Driverless, no driver needed
API / SDK / Libraries:C++ Obj-C C# VB.NET UWP Delphi Python Java Android LabVIEW
API / SDK / Libraries (TCP only):Javascript Node.js PHP
RoHS compliance:RoHS III (2011/65/UE+2015/863)
Suggested enclosure:YoctoBox-Long-Thick-Black-Vents
Harmonized tariff code:9032.9000
Cables and enclosures:available separately
Made in:Switzerland

1 These specifications are for the current hardware revision. Specifications for earlier revisions may differ.
2 The extended temperature range is defined based on components specifications and has been tested during a limited duration (1h). When using the device in harsh environments for a long period of time, we strongly advise to run extensive tests before going to production.

Accessories and related products

YoctoBox-Long-Thick-Black-Vents, Enclosure for Yoctopuce device (long thick black vents)Fix-2.5mm, screws and spacersUSB-A-MicroB-50, USB 2.0 type A to Micro-B data cable, 50 cmYoctoHub-Ethernet, Ethernet-enabled hub for Yoctopuce modules

Related articles and application examples


User manual (HTML)
User manual (PDF)
Product brief
3D file (STEP)
RoHS certificate
Most recent firmware52887 (01/25/2023)
Programming libraries61813 (07/05/2024)
Command line API61813 (07/05/2024)
VirtualHub application61813 (07/05/2024)

Add a comment 12 comments

1 - stefan Monday,october 05,2015 16H38

Is the sensor able to measure values between 0 and 4 mA?

2 - mvuilleu (Yocto-Team)Monday,october 05,2015 16H39

@stefan: yes, you can use the whole range 0-20mA if you want, this is a configuration option

3 - stefan Monday,october 05,2015 17H13

Thank you very much!

4 - guenter Friday,december 09,2016 13H11


We are thinking about extending our data logger software with support for this device.

If I understood the license terms of your C++ library correctly, it is allowed to embed and distribute your library into (resp. as part of) standard software tools developed by our company. Only executables or libraries are distributed, the source code of the product will not disclosed.

Please confirm if this is OK or let me know a suitable contact on your side to clarify details.


5 - mvuilleu (Yocto-Team)Friday,december 09,2016 13H31

@guenter Yes, this makes no problem: as long as the purpose of integrating our library is to use our devices, you can distribute it the way you want. There is no GPL code in our library.

6 - james275 Wednesday,february 14,2018 14H48

What would be the "state-of-play" regarding taking the information on the PC, and putting it into some form of Trend/Data Logging software?


7 - martinm (Yocto-Team)Wednesday,february 14,2018 15H08

@james275, have a look here:

8 - gaby_sh Thursday,january 24,2019 23H04

I try used the library for Javascript, but this its broken.
Can you help me please.


9 - gaby_sh Thursday,january 24,2019 23H15

the problems are in yocto_api.js line 199, line 2204, line 2259

10 - mvuilleu (Yocto-Team)Friday,january 25,2019 6H47

@gaby_sh The lines number seems to correspond to the code doing the HTTP request, in the old Javascript library. Note that library is now deprecated in favor of the Javascript/EcmaScript 2017 library, but nevertheless it is supposed to work properly. Did you start the VirtualHub application, and do you see your device in the VirtualHub ? What is the error message that you get ? Please send all information to support@yoctopuce.com

11 - robert@eriinc.com Friday,february 05,2021 15H17

Is it possible to directly communicate between the Yocto 4-20mA Rx and the Yocto RS485-V2? Specifically, I am looking for the ability to remap Yocto 4-20mA Rx values from the Yocto RS485-V2.

12 - martinm (Yocto-Team)Monday,february 08,2021 5H38

@robert : our devices are USB devices, they cannot communicate with each other automatically, you will need to run some software somewhere to control them.

Yoctopuce, get your stuff connected.