Questions Uni-T 61 C - Page 1
Forum section: electronics / beginners

author: BBK
author_rank: Newbie
timestamp: May 31, 2011, 02:12:44 pm
content: Hi,yesterday I received my Uni-T 61 C Multimeter from Hong Kong after 3 weeks of waiting.Now I saw that it has a COM Port and not as I think a USB connection whichthey sell in Germany. Can I use a normal COM to USB adapter for 6$ ?So and because Im a noob in electronic I wonder that the Uni-T shows volts beforeI will measuring a battery? Is it normal?RegardsSebastian

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: May 31, 2011, 07:00:28 pm
content: Quote from: BBK on May 31, 2011, 02:12:44 pmhypothetically , if the software that came with it ( or the latest for download ) ,has the ability to cooperate also with the USB models,I think that it will work .Sending an email to UNI-T about this subject , it would be an wiser move.About voltage indication in the mV range , its normal .If you cross the leads and the display goes to zero , then your multimeter works as it should .

author: Unknown
author_rank: Unknown
timestamp: May 31, 2011, 09:56:57 pm
content: One possible issue is that some RS-232 to IR cables use handshaking signals for parasitic power to drive the LED/photo diode. Fluke used to do that with their old RS-232 cables, and had a list of tested USB-to-RS232 cables that worked with their cable. No idea if this meter uses an IR connection and how it's powered.

author: BBK
author_rank: Newbie
timestamp: June 01, 2011, 11:45:11 am
content: I wrote Uni-T an Email but they write only:"You need to pay additonal USD 18.00 to have USB cable and connectivity from your buying shop "without any greeting or something else, very unprofessional.@kiriakosThanks I also saw that in the 100$ Shootout from Dave.Yes if I cross the lines it goes to 0 mv.@almShould the same like the Fluke the connection is only 1 Diode on the COM cableand one diode on the back of the UT 61 C.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 01, 2011, 02:25:10 pm
content: Quote from: BBK on June 01, 2011, 11:45:11 amWell you can see the glass of water as half full , and admit that you got an almost instant reply .I am sorry about the extra 18$ , it is a small boomer in comparison with other brands ,that they charge from 35$ - 500$ the PC connectivity accessory .And imagine that the price it does not cover just the USB modem , but also some portion goes for the software too.I would like to see an screen shot of the Uni-T software too ,currently I have explore the software that Agilent uses as Data logger,and shortly I will test and the DMM with it.If you like to see the Agilent data logging interface ,check this link ..https://www.eevblog.com/forum/index.php?topic=3259.0

author: sacherjj
author_rank: Frequent Contributor
timestamp: June 01, 2011, 04:50:24 pm
content: Quote from: Kiriakos-GR on June 01, 2011, 02:25:10 pmMost likely not. A COM port over USB looks the same to software as a serial port. From the programmers perspective, all that matters is setting the correct one in the config.

author: Unknown
author_rank: Unknown
timestamp: June 01, 2011, 08:37:16 pm
content: I would certainly try with an USB to RS-232 converter, I would expect it to work (although I wouldn't be surprised if it failed to work either). I tried the Fluke cable with a random USB to RS-232 converter and it worked fine (no idea if it was approved, was just a standard PL2302-based cable). A serial port is useful for electronics work anyway IMO, not all hardware and equipment has USB support yet, and if you're into micro controllers, something like a MAX232 is much cheaper and somewhat easier (DIP, although it needs some caps) than an FT232.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 02, 2011, 01:09:51 am
content: Quote from: sacherjj on June 01, 2011, 04:50:24 pmI will not argue , but my text was about branded solutions, like in this case an genuine UNI-T addon module.Or even the complete PC connectivity module ( USB - IR modem ) , that is made to attach at the specific multimeter.Our own friend here, got a bit unlucky , as he received an different revision of the same model.The main lesson from this story would be , to always contact the seller about this detail ,prior pushing the buy button.

author: tsmz
author_rank: Contributor
timestamp: June 02, 2011, 01:50:25 pm
content: Just as a note:The UNI-T USB adapter (I guess it's the same for the UT61C and UT61D, which I have) doesn't work as a USB-COM port, but as some kind of HID (input) device. So no luck in getting anything of value from it without using UNI-T's software.A screenshot of said software is attached, but it looks more like a tech demo than usable software. It works okay, but there's no real point in having a rather slow and clumsy data logger as a bonus. Communication seems to be one-way only, so you'll have to manually select the function you wish to use on the multimeter. I'd much rather have the serial interface so I can write my own piece of software.There's some protocol documentation and an alternative programhere.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 02, 2011, 03:28:06 pm
content: My congrats to you @tsmz .This page about the alternative program in Germany , is an true great find.http://www-user.tu-chemnitz.de/~heha/hs_freeware/UNI-T/I took the time to read for example the UT109.logBy this text " 1-5 Pakete pro Sekunde " I can estimate that 1-5 times per second as sample rate ,sounds ok ( at list for the hardware level ).By looking the screen shot, I had immediately realize that I have see this software and before.And another one Asian maker of DMM's , uses the same software too.QuoteFor your information the Adobe photoshop that is an software that is considered for profesional use ,it costs near to 1000$ or more .I got the old version 7.0 even as used for 450$ and some how I feel lucky.For the price that you payed about the UNI-T product , the data logger it is as a bonus.An useful bonus for young people and starters students.The professionals , will choose more matured solutions.Even so , If some one does not care for the data logger ,its best to not get this UNI-T range of models ,and select some one, more close to his own needs .

author: tsmz
author_rank: Contributor
timestamp: June 02, 2011, 06:26:31 pm
content: Quote from: Kiriakos-GR on June 02, 2011, 03:28:06 pmIt's the more or less detailed communication format for everything these meters will send to the PC. "1-5 Pakete pro Sekunde" is 1--5 (13-byte-) packets per second, which seems to be the update rate. Slower in AC and capacitance mode. I think it should be reasonably understandable, even without knowing German, after it has been put through a machine translation.What is the other brand that uses the same software? There's probably a possibility to get RS-232 adapters for their products for less money.QuoteOf course the software is only a bonus, but there's a point in having a data connection from the multimeter to your computer: Computer software is cheap, hardware in a multimeter isn't.You can do all sorts of postprocessing with computer software, so instead of getting a screenshot of the mulimeter's display, a rather useless autoranging graph that's only good for long-term datalogging etc., which is basically just a tech demo and not usable as a software, it would have been much better to design the software to include features the multimeter doesn't have. For example, define allowed value ranges and play a sound if a measured value is out of range--this would quickly allow testing lots of components without having to look at the multimeter or screen. (Another possibility is to play a sound if a component is within a defined range, for measuring a bag of identical resistors and getting the ones that are closest to the actual value etc.)The software's just a gimmick. Datalogging is nice, but the software could be greatly improved by reconsidering the functionality and user interface.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 02, 2011, 07:19:08 pm
content: Quote from: tsmz on June 02, 2011, 06:26:31 pmI do not remember the brand , there is one shop in Germany who had an amazing price for Rigol oscilloscopes with free shipping to Greece,and they had only this brand of DMM's in their product range .Quote from: tsmz on June 02, 2011, 06:26:31 pmAhh this is what the newest Agilent U1272A does( I am getting one soon).Well at the higher priced DMM's those advanced additions ,it does make the deference , but for the right price !!And as last , your are wrong about the concept that software is something cheap.I was for one decade member at betanews.com , and was downloading every day 15 updates,for the 15 differentfreesoftware packages , that they had limited functionality as software , and lots of bugs.And I came to the point , to say to my self , that I was following the wrong way .And so I followed the proper way, that is as one professional software package for every major interest of my .The complete toolbox for every task .It costs , it is legal , it is stable , and If I need help there is large communities with all the answers for me.

author: Bored@Work
author_rank: Super Contributor
timestamp: June 02, 2011, 07:22:07 pm
content: The availability of a protocol specification is a purchase criteria for me. I typically don't care much about included software. It is usually for the wrong operating system anyway.If I have the spec and if I need the data on a PC I look for, or write a Linux driver or protocol converter, and script the rest. The key is to get the data converted to ASCII. The rest is child's play. The worst is when I have to do a driver.I have a nice set of scripts for my bench multimeters, a few for my oscilloscope and some random stuff here and there for other equipment like programmable power supply and signal generator.

author: tsmz
author_rank: Contributor
timestamp: June 02, 2011, 09:29:39 pm
content: Quote from: Kiriakos-GR on June 02, 2011, 07:19:08 pmI'm not sure if you understood me correctly. Developing software is much, much cheaper than developing hardware, and developing PC software is much, much cheaper than developing embedded software.It makes sense to have only basic functionality on a handheld device. Inputting numbers on a multimeter or having a menu system to configure it is really annoying and will also, if not designed properly, distract from the stuff youwantto do.For more features, you'll need a bigger MCU with more storage and RAM, which will cost more. The software will also need to be tested more thorougly, which adds to the price of the finished product.PC software is virtually free, because you're basically unrestricted by storage space, memory consumption or processor speed.It makes total sense to include advanced features in your PC software, because that can be done without more expensive hardware. The UNI-T multimeters just contain a custom VLSI chip anyway, so there's probably not much in terms of features you'd be able to add even if you wanted to. No problem with PC software, because once you have the data, you can do everything you want with it. PC software is (virtually) free.QuoteThe proper way is to get the right software for your needs. There's a lot of professional free software out there, some of which works even better than commercial products.(Also, do you really have to put a space before every comma? It makes your posts very hard to read.)

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 02, 2011, 11:48:06 pm
content: Yes and no, yes and no, yes and no, ( comma practice )On topic,custom VLSI chipThis is the easy part , the easiest than all.You throw in the pot one Dave Jones, you add also one portion of Eagle software,plus some computing power, few grams of silicon ponder, add also few robots to solder iton the PCB, bake all the ingredients at 250C for two weeks, and there it is.About the softwareYou have to know exactly what the target user needs, and to make the software to fit at the shoes of this user.The user could be a damn electrician , who needs something easy to use and practical.And even if you are an SUPER monster as programmer, if you can not think as electrician or have some experience in the field,there is no chance to make anything acceptable or useful.About the industry and marketingYes this open source thinky sounds good, but the companies needs to offer products,that does not have similarities with the other ones, of their opponents.And so just forget the idea about common software platform about data logging.Software with basic functionality on a handheld device ? What ? what is this ?I will give an estimation here as opinion.The data logging report, it could be used even as evidence in a court house,that demonstrates, that for instance I got an Air condition that claims to use 2000W of power,and the damn machine was using 3500W, and my electrical bill got wild just from that.The lawyer, defender of the brand who made the Air condition,he will turn against me (the electrician) by accusing the equipment that I had use to take the measurement,as not authorized ones. ( electrical measurement tools and logging software ).What would possibly be my answer to that ?An economic DMM and some sort of freeby software that I got as gift ?Conclusion.Hardware and software about data logging are one solution, and as one solution,it must coming from an reliable source, so to be called as reliable too.If some one needs data logging for playing in the four walls of his home,he can use everything he likes.But the professionals ( technicians - scientists - factories - developers ), they can not.

author: BBK
author_rank: Newbie
timestamp: June 06, 2011, 09:15:21 am
content: I buyed the UT 61 C because of the temperature measuring and also that Ican log some temperature informations on pc.So whats now? You all mean that I can buy a normal USB to COM adapter?@tsmzThanks for the program, I will test it if my 61 C works with USB port.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 06, 2011, 10:21:34 am
content: Personally I would go for the genuine UNI-T USB to COM adapter.The construction quality, and the compatibility,it is given and signed by UNI-T.And this is what matters to me the most.And since when the no-name trash on ebay, called as normal ?

author: tsmz
author_rank: Contributor
timestamp: June 08, 2011, 09:42:09 am
content: Uni-T don't sell USB-RS232 adapters. They sell USB interfaces for their multimeters.You will most likely be able to use a generic USB-RS232 adapter for the RS232 cable. It's no rocket science and the data rate seems to be low, so there's not much you can do wrong. If you're just using it for one computer and just for the multimeter, you can pretty much buy anything.I might recommend getting a USB-RS232 adapter with a decent chipset, though. You see, all of them work, but they're vastly different in terms of driver support. I've come across a few adapters, and some of them are really dodgy. Prolific has about a dozen different revisions of the same chipset, each of which needs a new driver and you can only have one of them installed at a time. Drivers for the different revisions tend to be a tad hard to find, so I really can't recommend them, because it's just such a hassle getting the stuff to work! I don't even want to think about driver support for future operating systems, there's probably none (I don't really know, though). Nowadays, there seems to be a popular dodgy chinese chipset for low-cost adapters. That's okay, but as with all dodgy chinese chipsets, you'll probably never get any drivers for that which aren't included on the bundled CD.If you want to buy a USB-RS232 adapter for general use which should last you a while, I do recommend getting one with an FTDI chipset. FTDI's chipsets aren't cheap, but they have never disappointed (me, at least) in supplying new drivers for their products. It's just one driver for everything, so there won't be any horrible compatibility issues. Linux support is good as well, if that matters to you.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 08, 2011, 10:44:13 am
content: tsmz it looks that you had lots of free time, so to invest it and examine all those 6-7$ devices,so to form one acceptable opinion.Its fine with me to get what ever pleases you.But by getting it, you lose your right to complain about the product ( DMM ),if you face difficulties, as example: acts slower that your expectations.Simple as that.

author: Bored@Work
author_rank: Super Contributor
timestamp: June 08, 2011, 03:34:10 pm
content: Quote from: tsmz on June 08, 2011, 09:42:09 amProlific is a strange case. I yet have to find a Prolific P2303<x> based USB-RS232 adapter that didn't work out of the box on Linux. The driver comes with the kernel and just works. But for whatever reason Prolific really manages to mess up their Windows drivers nine out of ten times.

author: nukie
author_rank: Frequent Contributor
timestamp: June 09, 2011, 01:11:07 pm
content: Prolific is the worst USB-232 chipset maker, take for example those off market nokia mobile dongles they never work. There are plenty of them floating around and non of them work properly.

author: BBK
author_rank: Newbie
timestamp: June 15, 2011, 10:30:00 pm
content: So I received a Prolific (PL2303) adapter for 1 € (incl. shipping costs).The delivered driver doesnt work but I found a driver for 64 bit systems andWindows found driver and confirm COM 8 as the port for the adapter.But now I have some problems, the Uni-T Software shows an error without any connection"Network initialization failed. File or directory does not exist. File: C:/pdoxusrs.net. Permission denied. Directory c:/"I can confirm the error but you can switch on the COM Connection only COM1 to COM4.Now I tried with the german software (dmm.exe).It shows COM 8 and I can select UNI-T and now it shows"Wait for data"Any ideas?

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 16, 2011, 02:03:55 am
content: Quote from: BBK on June 15, 2011, 10:30:00 pmYes I have one but is not an idea, its a fact.You got scammed by getting a fake chip , an cheap replica.Every genuine Prolific (PL2303) are passing the test that the latest driver does to it.If it fails , its a fake .More info here.. last FAQ question ..http://www.prolific.com.tw/eng/FAQs.asp?ID=50Latest driver here . ( that probably works for the Agilent USB modem too, I will test it soon )http://www.prolific.com.tw/eng/downloads.asp?id=31Prolific offers their solutions only to branded manufacturers.