Tag: unit

UT61E Protocol Description

Posted by on March 18, 2013


The protocol used by the UT61e is quite simple, each packet contains 14 bytes. It constantly streams packets as the screen is updated at around 2 packets a second. The 14 bytes are basically a string where the range, digits, function, status are contained.

The serial interface settings are:

Describing the protocol:

This snippet shows you how the data is separated, I handle the 14 bytes as a string, which simplifies the process of separating each portion and since this is a low sampling rate application with low priority, it’s not a resource hog.

I believe the last two digits are the “end of packet” limiter (CRLF) however I currently cannot test this, I wrote the code a long time ago and I forgot to comment on this slight detail, but as you can see I’ve defined the CRLF contants, so it must be there.

A list of constants:

Here are some constants from my UT61e (unpublished) library…

That’s all for now, I currently don’t have a serial interface to test with (Ain’t got the USB cable either) so I can’t finish the library as to post it, but hopefully I’ll get it done eventually.

The supplied software by UNI-T is pretty bad and it’s Windows only, hence the drive to write my own.

As it is, it should give someone a head-start if they’re about to write their own front-end. On the datasheet of the UT61e controller it’s all explained in fine detail, but I can’t recall the number at the moment.

This whole thing was part of a bigger picture, but I had to give up the concept due to lack of funding.

Alright, enough of this shoulda, coulda, woulda!