UNI-T UT61E Multimeter teardown photos.

[Wytnucls]

No. The cable connection doesn't create a new COM port in the device manager list.
The only change I can see is the addition of a HID compliant device and USB input device in the Win7 device manager. Hope that helps.
I notice that the 61E logging program is similar to the 71B/D version, but with basic functionality only.

[Rick Law]

No. The cable connection doesn't create a new COM port in the device manager list.
The only change I can see is the addition of a HID compliant device and USB input device in the Win7 device manager. Hope that helps.
I notice that the 61E logging program is similar to the 71B/D version, but with basic functionality only.

Thanks!  That is exactly what I wanted to know.  I appreciate your effort.

I too wish the 61E's logging is better.  That is why I have in mind writing a "read com port and save to file" util  to collect the data point first and worry about how I juggle it later.

That in mind, may be I should resurrect my old (pre-XP) laptop with real RS232 or better yet, look for my HP200 - that very tiny DOS machine has a real serial port (via a dongle) - that bugger is smaller than the UT-61E, runs full DOS with a PCMCIA/Compact flash card as HDD.  Well, that should be a fun project (when I do find time for it).  I miss that little HP200.  Fun little machine.

Rick

[Monkeh]

The cable creates a standard 'USB to serial' interface. I don't see any proprietary interface.

No. The cable connection doesn't create a new COM port in the device manager list.

I'm not seeing your standard, non-proprietary interface.

[Wytnucls]

In 'Devices and Printers'

[Monkeh]

In 'Devices and Printers'

That's a name. Nothing more.

It's Windows. It's serial. It's not a COM port. Enough said..

[Wytnucls]

I never said it was a COM port.
I said there is no new COM port in the 'Device Manager' list.
Now, if you think it creates a new COM port, good for you. I'm not terribly interested anyway. 
Buy the frigging cable and leave me out of your hacking efforts.

[Monkeh]

I never said it was a COM port.

Never said you did. You did however claim it was some sort of standard interface, which, seeing as it's not a COM port..

Now, if you think it creates a new COM port, good for you. I'm not terribly interested anyway. 

Uh, okay, whatever.

Buy the frigging cable and leave me out of your hacking efforts.

......... Sorry, I don't even know what the hell you're saying there.

[notsob]

THE 'friggin' cable'   UNI-T UT-D04

http://www.ebay.de/itm/UNI-T-UT-D04-USB-INFRARED-INTERFACE-CABLE-UT71-UT81B-/360492337463?pt=LH_DefaultDomain_0&hash=item53ef048937

or buy one from Franky ( massively better service )  my order was posted in HK on a Friday and was Delivered in Australia on the following Tuesday

[mariush]

I don't understand why you don't just get one of the serial to usb adapters I linked to, or something similar. If for some reason it doesn't work with your computer, it's just 3-4$ wasted and you can get another model.

It shows up as a regular com port, the data the meter sends is well documented in the chip datasheet ... it's nothing special about it, just playing with the bits in a fixed set of character the meter sends twice a second.

[Monkeh]

THE 'friggin' cable'   UNI-T UT-D04

http://www.ebay.de/itm/UNI-T-UT-D04-USB-INFRARED-INTERFACE-CABLE-UT71-UT81B-/360492337463?pt=LH_DefaultDomain_0&hash=item53ef048937

or buy one from Franky ( massively better service )  my order was posted in HK on a Friday and was Delivered in Australia on the following Tuesday

I know which bloody cable it is. I even have the schematic. It uses a cheap chip from a dead company. The UT-D08 is a better choice by far.

[Rick Law]

I don't understand why you don't just get one of the serial to usb adapters I linked to, or something similar. If for some reason it doesn't work with your computer, it's just 3-4$ wasted and you can get another model.

It shows up as a regular com port, the data the meter sends is well documented in the chip datasheet ... it's nothing special about it, just playing with the bits in a fixed set of character the meter sends twice a second.

re: why you don't just get one of the serial to usb adapters...
I actually did - it just arrived DOA.  Plus my other two existing ones I have that didn't work.  That is zip for 3.  I would be foolish to order a forth and just hope.  Thus I looked into the UT's USB cable.

- - -

re: It shows up as a regular com port, the data the meter sends is well documented in the chip datasheet ... it's nothing special about it...
Exactly.  The UT61E-RS232 works on my desk top, I can see the bytes coming in with just a few lines of code.  I just can't move my desktop around easily; but my laptops have no RS232.  Since I am not particular about plotting it, thus the thought:, argh, I will just write some C or even Basic, and run it off my old (DOS-era) laptop with real RS232, dump the data into a file, now I can convert the data to whatever form I want to plot.

- - -

Those back-and-forth just kicked up some nice memory - Remembering I have two Hp200Lx is kind of nice.   That little tiny DOS machine (with real RS232) is smaller than the UT61E itself and run on two rechargeable AA cells.  I can actually have some good data collection/plotting capability that I can move around easier than I can move my laptop.  That would be a fun little project to do.

[T4P]

UltraDMMs creator has spoken up about it before on the thread, it's recognized as a HID device not a COM device

[Rick Law]

UltraDMMs creator has spoken up about it before on the thread, it's recognized as a HID device not a COM device

Arrgh...

I spend so much time reading to learn about the UT61E as I was waiting for mine... I forgot what I did read...

Sorry for the repeat.

[gatos]

See if you experience the same problem with UltraDMM : http://www.ultradmm.com/

Dear maruish, I am back!
I installed .NET in my laptop (I had to find on offline installer), and I installed UltraDMM as well.
I have to say that it is really a powerful software with many capabilities and a very nice GUI. But my oldie laptop (Celeron 333MHz) was placing a lot of effort to cope with it (always above 90% CPU usage).
Anyway I tried some measurements, they were fine apart from the frequency measurement: the meter shoes 50.0 Hz and the software displays 500 mHz.

Thank you very much for your proposal (very nice software indeed)!

PS still waiting answer from Uni-Trend.

[dr_p]

I installed .NET in my laptop (I had to find on offline installer), and I installed UltraDMM as well.
I have to say that it is really a powerful software with many capabilities and a very nice GUI. But my oldie laptop (Celeron 333MHz) was placing a lot of effort to cope with it (always above 90% CPU usage).
Anyway I tried some measurements, they were fine apart from the frequency measurement: the meter shoes 50.0 Hz and the software displays 500 mHz.

Thank you very much for your proposal (very nice software indeed)!

PS still waiting answer from Uni-Trend.

UltraDMM seems to require a 2GHz CPU, so your problem is not necessarily from the meter, but maybe from the software.

[gatos]

I know that about UltraDMM, but I wanted to honor the author of the software by testing it since he proposed it!
I am absolutely sure that my meter has no problem in the frequency measurement (triple checked with other multimeters).
The problem lies on the software (the software of Uni-Trend as well-see my previous posts).

[gatos]

Dear sirs,

I have one question for you. I own an old Summit SDM383 (non TrueRMS), a recently bought Vichy VC99 (non TrueRMS) and a recently bought UNI-T UT61E.

I friend of mine brought a Fluke 79 III, so I took advantage to take some measurements.

           230V AC                 UPS output            12V DC                     1.5V DC           200Ohm Resistor
              (grid outlet)   (modified sinewave)   (old 23A battery)        (AA battery)           (2%)
79III          237                        235.5                      9.5                              1.469                  199.8
SDM383     234                        205                      11.08                              1.485                  193.8
VC99         237                        205                       11.02                             1.468                  200
UT61E       238.5                     236.3                    11.03                              1.468                  199.87
 

Unfortunately Fluke has not been calibrated for the last 4 years.
Do you consider wise to “calibrate” my other multimeters according to Fluke measurements?

Especially for the 23A battery, I think Fluke puts a lower resistance so it draws more current from the battery trying to show if the battery is able to deliver power. I won’t change anything here.


I am looking forward for your valuable opinions.

[T4P]

It looks painfully obvious NOT to calibrate according to the Fluke especially when it doesn't have less accuracy rating than the UT61E plus it hasn't been callibrated for 4 years

It doesn't look obvious enough?

[Lightages]

Never adjust one meter to another without knowing which is correct. One of the multimeter check devices from Doug at voltagestandard.com is a worthy purchase for anyone worried about the accuracy of their measurements. They aren't very expensive and seem to be reliable.

Just because the one meter is a FLuke does not mean it is more accurate than the UNI-T.

[Monkeh]

Especially for the 23A battery, I think Fluke puts a lower resistance so it draws more current from the battery trying to show if the battery is able to deliver power. I won’t change anything here.

Why don't you check that? Because it should be the same impedence. Which means the Fluke is badly out of spec on DC volts.

[gatos]

At T4P: it is obvious. But don't you think that I should tweak up a little bit the Summit on AC Voltage?

At Lightages: I agree with you. I would like to get a "DMMcheck Plus" in the future.

At Monkeh: Unfortunately Fluke is away. I wouldn't say that Fluke is out of spec on DC volts (check the measurement on the 1.5V battery). Because the 12V battery (type 23A) was used, I think it had a way to tell the user that this battery is of no use anymore. Remember some old-cheap multimeters that they had a special range for measuring 1.5V and 9V batteries?
Maybe Fluke implements this kind of measurement? Just a guess!

[Lightages]

Don't tweak anything without knowing which is wrong. No Fluke ever had a battery test function. The input impedance of multimeters is 10megohm, or more. There is no way for that fluke to load that battery to give a lower voltage. It appears to be out of spec as has already been said.

[Monkeh]

At Monkeh: Unfortunately Fluke is away. I wouldn't say that Fluke is out of spec on DC volts (check the measurement on the 1.5V battery). Because the 12V battery (type 23A) was used, I think it had a way to tell the user that this battery is of no use anymore. Remember some old-cheap multimeters that they had a special range for measuring 1.5V and 9V batteries?
Maybe Fluke implements this kind of measurement? Just a guess!

I assure you, it does nothing of the sort. That Fluke should have 11M across it in VDC at that range. It is wildly out of spec.

[ddavidebor]

in fact, chinese meter usually have good calibration.

i've never found one out of specs when new... (something under 20$, but it's rubbish)

[T4P]

AC Voltage? That thing is TrueRMS! So really don't attempt it.
Best step here is get the UT61E callibrated and use it to callibrate the 79III and the others