Two UT61E, serial ports and DIY soft for plotting U2=f(U1) [need help] - Page 1
Forum section: electronics / projects

author: 001
author_rank: Super Contributor
timestamp: April 08, 2014, 07:19:22 am
content: Hello!I`m looking for way to draw graph U2=f(U1).Actually I2=f(U1) for MOSFET disquisition, but it does not matter:What I have:twopopular UT61E multimeters with RS232 connection and PC (Windows 8 ) with two serial ports (connection is OK).What I can: I can write html-aplication GUI with javascript for plotting (.hta)What I`m not understand: how to transmit data from UT61E to my application?It may be wrong way to use .hta, but now I can write it onlyI`m homebrew entusiastWhere I can find some tutorual for similar problem? Step by step?Thanx!P.S. I find original soft (http://www.uni-trend.com/Web%20site/DMM%20Software/UT61E_setup%20v2.00.exe), alternativehttps://www.eevblog.com/forum/projects/ultradmm-software-project/something elsehttp://www-user.tu-chemnitz.de/~heha/hs/UNI-T/But how this programs reads data from serial port?

author: mariush
author_rank: Super Contributor
timestamp: April 08, 2014, 03:57:09 pm
content: Download UltraDMM , add two ut61e meters in "Manage meters" window, each with its own serial port.Connect to both meters, open Tools > Meter log and wait for the software to log all the information then you can export the data for each meter to xml or csvThen you can import the csv files into your application and plot whatever you want.I don't see any way for ultradmm to dump to disk the records as they are read, so I'm not sure you can do it in realtime as you get data from meter.The protocol for the UT61E is well documented, you could in theory get the raw bytes from the serial port and decode them yourself. It's not hard. I'm just not sure how you'd connect to serial using Javascript.

author: 001
author_rank: Super Contributor
timestamp: April 09, 2014, 01:24:41 pm
content: Thanx for quick respond!Quote from: mariush on April 08, 2014, 03:57:09 pmOk. What is right way (or common) to do it? Where I can read similar example?

author: mariush
author_rank: Super Contributor
timestamp: April 09, 2014, 02:37:55 pm
content: The datasheet for the chip used inside the multimeter is here:http://www.alldatasheet.net/datasheet-pdf/pdf/456295/CYRUSTEK/ES51922.htmlPages 21-25 explain the serial output and how the data is sent... basically, it's a sequence of 1 and 0 for each lcd segment on the screen.note: the data is plain available with the clasic serial cable ... you just connect with the proper bitrate and data comes in.. it's just a meter->pc link, there's no talking back to meter.If you have the cable with usb jack at the end, it may be a bit trickier (ask the guy that makes ultradmm to tell you how he reads that).

author: 001
author_rank: Super Contributor
timestamp: April 09, 2014, 06:58:31 pm
content: Quote from: mariush on April 09, 2014, 02:37:55 pmI`m know all of that. But can I try any data from serial port via javascript?

author: mariush
author_rank: Super Contributor
timestamp: April 09, 2014, 07:05:40 pm
content: Have you tried Google or are you just waiting for someone to give you everything ready made?Try this:https://www.google.com/search?q=javascript+serial+port&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb

author: Bored@Work
author_rank: Super Contributor
timestamp: April 09, 2014, 07:31:13 pm
content: Quote from: 001 on April 09, 2014, 06:58:31 pmThere would also be the option of learning a real programming language and an OS' API, instead of hobbling along with JavaScript, the makeshift joke known as node.js and some dubious node.js serial driver.

author: Harvs
author_rank: Super Contributor
timestamp: April 09, 2014, 11:53:46 pm
content: If you're trying to make that plot of a mosfet using multimeters it's going to be very difficult.Problem is those characteristics of a mosfet are very temperature dependent, and as soon as you dump a couple of amps through a FET it'll warm up very rapidly.The typical way to do this is to excite the gate of the mosfet with a waveform (just a sine wave from a sign gen) and record the values using a scope or the like. Then you just do XY plots on the PC of whatever variables you want to compare. That way you record all the data points you need in a fraction of a second before the thermal shift starts to kicks in. Where as a DMM will take several seconds to do a single curve.

author: 001
author_rank: Super Contributor
timestamp: April 12, 2014, 03:53:44 pm
content: ok, its bad news for me