UNI-T UT61E

UNI-T UT61E

Status	supported
Counts	22000
IEC 61010-1	CAT II (600V) / CAT III (300V)
Connectivity	RS232 / USB
Measurements	voltage, current, resistance, capacitance, frequency, duty cycle, diode, continuity
Features	autorange, true-rms, data hold, min/max, relative, bargraph, backlight
Website	uni-trend.com

The UNI-T UT61E is a 22000 counts, CAT II (600V) / CAT III (300V) handheld digital multimeter with RS232 or USB connectivity.

See UNI-T UT61E/Info for more details (such as lsusb -vvv output) about the device.

Hardware

• Cyrustek ES51922 multimeter chip (ES51922A actually, as per various photos: 1, 2, 3, 4)

Photos

Older version:

• 
• 
• 
• 
• 
• 
• 
• 

Newer version:

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

Protocol

See Multimeter_ICs#Cyrustek ES51922 for the DMM IC protocol.

Depending on the cable, additional decoding is needed, though.

Different cables are available to communicate to the DMM: regular serial cables which provide a COM port, and USB HID based cables where applications are required to handle a proprietary protocol of running serial communication on top of HID requests. See the Device cables page for details, the same cables can be used with many different DMM models.

Depending on the specific cable in use, either a device driver ending in -ser or not ending in -ser must be used. See README.devices for details.

The transmission of the measurement data cannot be disabled, the respective Cyrustek ES51922 pin (111, RS232) is tied to GND (i.e. transmission is always enabled) on this multimeter.^[1]

Usage

The following sigrok-cli command can be used to receive measured values from a device connected via USB (note that the USB VID/PID after the conn option needs to be changed depending on the exact USB adapter cable used):

$ sigrok-cli --driver=uni-t-ut61e:conn=1a86.e008 -O analog

If your meter has a serial (RS-232) cable connected to a USB-to-serial adaptor, a different driver is used. Example for ttyUSB0:

$ sigrok-cli --driver=uni-t-ut61e-ser:conn=/dev/ttyUSB0 -O analog

With the --samples <n> option it is posible to stop the acquisition after the specified number of measurements. More information can be found in the README.devices file of the libsigrok source tree.

Resources

• Manual
• Vendor software
• Henrik Haftmann: DMM.exe etc. (Windows software for various UNI-T DMMs, and lots of device/protocol info)
• Henrik Haftmann: Hoitek HE2325U info
• Henrik Haftmann: UT61E log and protocol docs
• diyftw.de: Uni-Trend UT61E (UT-D04 linux treiber) (device info, Linux software using HIDAPI: ut61e-linux-sw-0.02.tar.gz)
• Steffen Vogel: UNI-TREND UT61E Digital Multimeter (device info, Linux software for serial port: dmmut61e-0.01.tar.gz)
• Multimeter data parsing utility complete implementation written in Python
• Steffen Vogel: Inner workings of UNI-TREND UT61E Digital Multimeter (teardown)
• erste.de: UT61 - USB Multimeter unter Linux auslesen (info on the Hoitek HE2325U (clone?) and how suspend/resume fixes some issues with it)
• easyelectronics.ru: Refinement of a file multimeter UT61E
• flodins.info: Multimeter UNI-T UT61E
• UNI-T UT61E schematics: ut61e sch.pdf
• Teardowns: 1, 2, 3, 4, 5, 6