UNI-T UT61E Multimiter Serial Protocol Reverse Engineering

UT61E is a fantastic multimiter for the price that unfortunately comes with a terrible PC interface program:

9-17-2015 8-13-09 PM

I decided to poke arround and see if I can reverse engineer the serial protocol that might be useful for someone who would like to try to write a different software or maybe even use my SerialChart software.

So here is what I found using a serial monitor: 

9-17-2015 8-14-14 PM

The serial settings are as follows :  19200bps , 7 bit, Odd Parity, 1 Stop bit.

9-17-2015 8-13-41 PM

To start streaming data you must set the DTR flag , to stop clear the DTR flag. Simple.

9-17-2015 8-14-48 PM

Now regarding the numbers. What do they mean ?

In Voltage mode, the first digit is number of decimal points shift (+1), and then follows the value, so for example 

107393  corresponds to  07.393V  (note dot is after  1 +1 = 2nd digit in value)
201348 corresponds to  013.48V  (note dot is after 2 + 1 = 3rd digit in value)
110822 corresponds to  10.822V  (note dot is after 1 + 1 = 2nd digit in value)

As far as 000:0 it appears to always be the same in. 

The format appears to be different in Ohms range, for example:

000106300020  corresponds to 1.06Ohm
000004300020 corresponds to  0.04Ohm
504833300020 corresponds to 4.833MOhm

So again first digit appears to be a multiplier.

Hope this helps to anyone who wants to take it further .. 

Update 2/18/18: Found this resource that might shed some more light on the protocol http://gushh.net/blog/ut61e-protocol/


3 thoughts on “UNI-T UT61E Multimiter Serial Protocol Reverse Engineering

  1. Rafael Reply

    Thank you very much for your page; not only I was able to connect to my UT61E, I also found a great terminal program (Termite).

    One interesting detail: on my meter (UT61E bought new in 2017) I was only able to display meaningful information when using 19200 7N1 (instead of 19200 7O1). Quite weird

Leave a Reply

Your email address will not be published. Required fields are marked *