Hi all,
I have got this device for a while, successfully used with Windows 7 in the past, but since I moved to W10 the USB driver remains faulty and I cannot use PC Link possibilities. I have followed the " Installing the driver for Windows 8 - 8.1" instructions, but it doesn’t work. Does anyone knows how to configure this stuff properly ?
Thanks
Hi,
You should post your question in this link.
http://www.velleman.eu/support/contact/?product=372236
Thank you for your help.
I have already sent requests to Velleman support. I never get any answer.
Hi Laurent31,
Yesterday by chance I wanted to connect my dvm1200 for the first time to my laptop which runs Windows 10 and then I saw your post. After a few hours I finally got it to work on my Windows 10 
So I thought let’s create an account and share my solution. I will describe my problem and solution, and probably you will have the same problem 
I followed the instructions on the website but unfortunately when I go to device manager I still see a yellow exclamation mark and the COM port status gives an error 10.
So the problem is that dvm1200 uses an outdated chip (which is located at the end of the cable, where it is inserted in the multimeter) to convert the optical signal from the multimeter to the pc. The chip used in the dvm1200 cable is an old revision of the ‘prolific 2303’ chip which is officially not supported anymore from Windows 8. Prolific only supports the latest two revisions of this chip, the reason for this is because from all other revisions there are more Chinese clones on the market than official chips. Anyway luckily some people found out that some old drivers still work on Windows 10 with this chip. The following page will describe how to install and download these old drives such that the COM port will work properly. leftbraintinkering.blogspot.nl/2 … evice.html
So my COM port worked now and I received data. I checked this with the program ‘putty’. You can also check this but for now I would skip this part. So my next problem was that when I downloaded the Windows 7 software from we.tl/HOW9okhgjP
One last thing you mentioned you also followed the windows 8 – 8.1 instructions. I really recommend you to reverse back the changes you made in step 4 and step 9 since this could cause security issues and perhaps will give problems and headache in the future.
Please let me know if you succeeded.
Oh and then the really last thing: In case you want to check the incoming data from the COM port install ‘putty’ or ‘realterm’ and open the correct COM port. The baud rate should be set to 2400. If you receive data the command window will start showing characters. Don’t expect comprehensible data; you will probably just see crap, this is because the way the protocol is implemented and how the data is represented to you. If you see data you know it is good.
@velleman perhaps you guys can make the PC-LINK software delivered with the multimeter on my cd available on the dvm1200 page since I can’t find it there.
Dear Mennotjer,
Thanks so much for this incredible job, this was very helpfull for me. It is a joy to see that there are people willing to help other well !
I have scrupulously applied the procedure to install the old driver and it works on a devices manager standpoint : The Prolific device is seen on COM3 and it’s said it works properly. No more yellow triangle ! I installed Putty and opened a session for serial lines (COM3, 2400 Bauds) but it seems to hear nothing from the Prolific. The window remains empty, even with multimeter connected in PC-Link mode. Regarding Realterm, it doesn’t work on my computer.
Nevertheless, I have installed three versions of PC link : The one supplied on CD with the multimeter in 2012, the PC Link 6000 version you made available and finally the version available today on Velleman website. None of them gave any positive result. Each time, I have followed the same procedure :
Here is a summary of how impossible it was to establish the link : https://we.tl/rTPETnJBoL
Do you have any idea what I did wrong?
Thanks
Laurent
There are a few things I could think of.
First it seems strange that putty didn’t show any data. you wrote realterm didn’t work but that could be because there are different versions available on the internet… This realterm installer runs fine on my windows 10: sourceforge.net/projects/realterm/ Before starting the program connect the cable to the PC and check in the device manager which com port is assigned to the prolific device. Now start realterm. In the ‘display’ tab set ‘display As’ ‘Hex[space]’, leave all the other settings untouched in this tab. now go to the tab ‘Port’ set ‘Baud’ to 2400. Select from ‘Port’ the corresponding COM port. probably COM3 (by the way my PC also sees the profilic as COM3). At last press the ‘open’ button next to the field you just set the COM port. Stay in this ‘port’ tab.
Now connect the multimeter to the other end of the cable and enable the PC-LINK mode. Data should now appear in your realterm window. The data will look something like this:
1b 27 3d 4d 5b 65 7b 87 9e a0 b0 c0 d4 e0 in a repetitive way. In the ‘port’ tab all the way on the right side you see Status. The box before RXD should start to blink. If you still don’t see any data appearing on the screen there could be perhaps a problem with the cable or multimeter, although you wrote that you succesfully used this multimeter on your windows 7 so I assume the cable and multimeter are not damaged. Note that you won’t see data if you pressed the ‘hold’ button on the multimeter itself (which is kind of logic since this is what hold means). Also just double check if you really use the good profilic driver version.
Ok concerning the problems with the PC-LINK software, I had the same problem, where you don’t see the correct COM port or only COM1. When I start the program as administrator by right click on the PC-LINK icon (on your desktop) and select ‘run as administrator’ the COM ports will be available to select. I hope this helps.
If something is unclear let me know. I’m not at home at the moment otherwise I would have added some screenshots.
OK, I found why Realterm was not running fine, I should have launched it as an administrator. Once done, I can now read the hex data from the multimeter (just one set, after that it’s seems to be frozen).
Following your great tips, I have tried to run the 3 versions of PCLink as an admin. The PClink 6000, if I understand, scans automatically the serial ports. Unfortunately it obstinately refuses to connect to the COM3, on which the device is however connected. With the two other versions, same behaviour : The right port, COM3, is now proposed in the drop down list. Once selected, the multimeter launched in PCLink mode, as soon as recording start button is clicked, a message “error reading comm device” pops up as a machine gun ! I had to kill the task in order to stop PCLink. What a mess…
Haha, I also got the machine gun experience with the pc-link software I downloaded from the Velleman webpage. But in some way this is good! This message only pops up when an unexpected data package is read from the COM port, meaning you received data from the multimeter 
Also the fact that you saw data in Realterm is promising. Although it is strange you only saw one sequence. Did you installed the version of Realterm I posted in my last post?
Anyway the first character of each hex digits is ascending. So 1x 2x 3x … 8x 9x and then the pattern repeats itself, the x represents some varying value between 0 and 9 or A and F. So my data sequence goes up to 9x while I found that some people’s multimeter only go up to 8x ( gist.github.com/m0n5t3r/4543215 see this website where somebody wrote a Python script to read out the multimeter without the PC-LINK software, I’m a programmer so I adjusted some things, but it didn’t work for me). So the reason the PC-LINK program starts firing this error messages is probably because it expects a sequence of data from 1x up to 8x. I guess the PC-LINK 6000 Software expects up to 9x and is therefore working for me.
So I just came home and did some testing to confirm my assumption: I started the pc-link software, I downloaded from the Velleman website. Then I selected the correct COM port and pressed start. The multimeter wasn’t connected yet. Now I connected the multimeter, still no error messages. Immediately when I enabled the pc-link mode on my multimeter, error messages started to pop up. Now I pressed as quick as I could the ‘Hold’ button on my multimeter. Now the error popup windows stopped firing. When I pressed hold again the machine gun continuous. So this kind of concludes my assumption. Good news for you because you indeed receives data.
I didn’t realize the PC-LINK 6000 software scans for the correct COM port automatically but yes indeed it does. It starts searching for the COM port after you press ‘Start’. At the bottom on the left side of your program window, you should see the text “stop” which changes into “detecting” when you press ‘start’. The field next to this text indicates the COM port. It changes from 1 to 10 and then from 1 to 10 again. Sometimes it doesn’t find my multimeter and I need to repress ‘start’ for 3 times (at least that was the max numbers of tries before it finally connected). When the software finds the multimeter the “detecting” field will change into “linking”. Data will appear and a line is plotted in the graph. What works best for me is this order: First insert the cable in the pc and in the multimeter. Next, I enable the multimeter and set it in pc-link mode. At last, I start the pc-link 6000 software and press ‘start’. Only in this order, the software seems to find my multimeter most of the times after one try.
I really hope this works for you.
I pushed a little further the tests with Realterm. Here is a sample of what I get : https://we.tl/4qXFMsJESM. First of all, as you will see, the increasing first digit that you’re speaking about disappears very early in the flow transmitted 
. The error status appears also very early, not to say from the start of communication, in any case too fast for me to see normal operation before.
The screenshot you see here was triggered after the flow freeze. After several tries, I found that the length of the flow captured before the transmission freeze was very variable, sometimes very short. The one I present here is one of the longest. I tried to change some settings, but without success. I must say that I am not very stuck in communication protocols…
[quote=“Mennotjer”]At the bottom on the left side of your program window, you should see the text “stop” which changes into “detecting” when you press ‘start’. The field next to this text indicates the COM port. It changes from 1 to 10 and then from 1 to 10 again. Sometimes it doesn’t find my multimeter and I need to repress ‘start’ for 3 times (at least that was the max numbers of tries before it finally connected). When the software finds the multimeter the “detecting” field will change into “linking”.[/quote] Indeed I had noticed that the software scanned the ports, unfortunately in my case it goes from 1 to 10 without ever seeing that Prolific cable is on the com3 and without ever switching to Linking status. In fact, it stops scanning and hands
I have repeated the procedure 25 times in a row, having started in the order you are advocating. Each time, the ports from 0 to 10 were scanned, unsuccessfully, and the software returned hand.
I downloaded your file but although the file is called “Realterm failures.pdf” the content only consists of screenshots of the pc-link software (actually the same as you posted a few days ago). I think something went wrong. I hope I can detect some pattern in your screenshot although I’m afraid not, I don’t understand why it doesn’t work for you.
[quote=“laurent31”]I pushed a little further the tests with Realterm. Here is a sample of what I get : https://we.tl/4qXFMsJESM. First of all, as you will see, the increasing first digit that you’re speaking about disappears very early in the flow transmitted 
. The error status appears also very early, not to say from the start of communication, in any case too fast for me to see normal operation before.
The screenshot you see here was triggered after the flow freeze. After several tries, I found that the length of the flow captured before the transmission freeze was very variable, sometimes very short. The one I present here is one of the longest. I tried to change some settings, but without success. I must say that I am not very stuck in communication protocols…[/quote]
One idea but it is a long shot is that you install the newest drivers of the prolific web page leftbraintinkering.blogspot.nl/2 … evice.html . This is exactly what I did and perhaps the installer from the prolific website installs something additional??? Tomorrow I will make screenshots of my device manager such that we can compare all our driver versions for the prolific chip.
Oups… sorry for this misfire, here is the good file : https://we.tl/pIcGKvVK4j
I did what you said about reinstalling drivers. There is a difference in Realterm behaviour: No more freezing, CTS DCD and DSR lines in green as you can see in the second screenshot, also RWD line blinking in yellow (not visible on the screenshot) but always and unfortunately the error message !!
Regarding PCLink 600, it plays the same song : scans two times, find no COM port suitable to its taste and stops…
I thought the problem should come from the the USB hub on which I plugged the Velleman cable. I discovered that plugging it in a another USB socket of the Mother Board made the prolific driver faulty again. But after reinstalling it (3.3.2.102 version) there was no change, error in transmission is still present. I checked with USB 2.0, USB 3.0 and USB 3.1 sockets: Same result.
I’m gonna buy a gun (not a Velleman) and shoot me down…
Hi,
I didn’t have much time yesterday so couldn’t reply. So I checked your screenshots and the data actually looks really promising. Also I noticed that there is a difference in your data and my data. My data goes from 1 up to F while your data goes from 1 to E. The link I sent from the guy who build a python script also had data from 1 up to E.
The reason the pc-link 6000 isn’t working is probably because it searches for a com port with data that also contains a Fx byte.
you also mention CTS DCD and DSR lines are green which is great. Nevertheless I see there is a UART receiver framing error which I also have but this could cause the error message in the other pc-link software.
I want to examine your data more closely so could you store the output from realterm to a file for me? This can be done in the tab ‘capture’. I made a screenshot of how the settings should be set to record data. 120 seconds of data will be enough. what I would like you to do is start capturing data and then measure something with your multimeter, like put the probes in your power outlet such that the multimeter measures 230 V. Then within this 120 seconds also measure the ground or a different voltage such that different data is sent to the computer. Note that the path in the ‘File’ field you need to set in realterm gives an error if the temp folder doesn’t exist. When the capturing is finished please post the recorded file. probably if you try to read the file with notepad you will see just a bunch of crap, which is ok because I can process this crap and simulate your multimeter. One last thing you mentioned that you have a different program next to the pc-link software from the website and the one you got from me. Could you also add that such that I could test it.
screenshots of my realterm and screenshot of the profilic drivers: we.tl/DSqWA20Q6i
Dear Mennotjer,
Thanks again for the time and brain Watts you are spending around my puzzle!
I executed your instructions. Something bizarre happened during the manipulations: Once again, when I plugged the cable, the port showed a yellow triangle in the device manager. I reinstalled the driver 3.3.2.102 and as soon as done, the computer offered me a splendid BSOD. I shot this BSOD in case you would be able to conclude something from the error code. Here is the picture : https://we.tl/wnmWGH1iNA
Two rebooting of the computer were necessary to give him the ideas in order after this crash. But now everything works and I could record with Realterm and the multimeter. During recording I took the probes around the terminals of two old lead batteries. Here are the 120 s recording data file https://we.tl/A5X5fuSwER
And finally you will find here the genuine software bundle I had with the meter in 2012 : https://we.tl/kUz2SEGkuY
So I did some tests with the data you recorded for me. I think I have an idea how to get it to work. The reason why we got all those error messages is probably because of the uart frame error. My solution was to create a virtual com ports with the free software com0com and redirect the data from the real com port to the virtual one with the help of realterm. The virtual com port now doesn’t seem to have uart frame errors. In the pc-link software, from the velleman website, I selected the virtual com port and then I had no errors popping up and data started to be visible Is it correct that your battery was 12.8V ? The pc-link software was working but not fully correct yet, because I didn’t had the time to fully simulate your multimeter with the data file you gave me. Anyway before I start spending time to fully simulate your multimeter I thought let’s test it already at your computer. My multimeter outputs slightly different data so I couldn’t use that one. This is also the reason why the pc-link 6000 software doesn’t work with your multimeter. (haven’t tested yet the pc-link software btw you sent). ok so this are the steps I took:
You can only create com pairs and no separate com ports. So what we are going to do is redirect the input from the multimeter (com3 for you) to com9. com9 will send its input to com10. com10 we use in the pc-link software.
so now we’re gonna redirect the multimeter input. Start realterm and open COM3 with baud 2400. Now go to the tab “echo port”. In this tab select port COM9 and enable the checkmark at ‘echo on’. just to be sure, you can set the baud at 2400, although I don’t think it is necessary.
To test if this works set your multimeter in pc-link mode and check if data is visible in realterm. To check if data is redirected check if in the “echo port” tab the ‘TXD’ at the bottom of the window is blinking yellow. Now disable your multimeter but keep realterm open.
start the pc-link software and select COM10. Then press ‘start’. Now enable your multimeter again and set it in pc-link mode again. Now the pc-link software should show data.
So before you use the pc-link software you always first need to redirect the com port with realterm. The virtual com ports will remain, even after reboot.
let me know if it works, if it doesn’t I will do more test.
Btw I never tested it, but indeed if I put my cable in a different usb, the drivers will reset to the latest version which results in the yellow triangle, so we have the same behavior. As for the BSOD I didn’t look into it but hé it’s Windows…
OK, I’m back this morning and immediately applied your instructions. Once comOcom tuned, RealTerm’s echo port tab shows bottom left TXD in yellow, but not blinking. I then started PCLink as an admin (downloadable version on Velleman’s web). The ports proposed in the list, in my case COM20 and COM21 are the comOcom pair because the lower numbers were all allocated it said. I therefore selected port 21, which it answered instantaneously: INVALID PORT NUMBER. Il also tried with the two other versions of PCLink without more success. But using PCLink 6000 and seeing it scanning COM ports from 1 to 10, I realised that probably no PClink version was designed to accept a port number over 10. I then went back to comOcom and forced it to accept COM numbers between 1 and 10, being sure that nothing was physically connect to the said numbers. Using again the last PClink version, I retried to connect. COM9 port, the second port declared in comOcom, was effectively seen by the software and its selection accepted. When I clicked the start button, it happened… nothing :((((((((((((((((((((((((((((((((((((((((
Let verify if there was actual output on your COM9 port.
So if I understand it correctly your connection flow looked as follow:
[device | output ] → [input | program | output] → [input | program | output ]
[Mulitmeter | cable] → [COM3 | Realterm | COM?] → [COM9 | pc-link | nothing happend ]
Where you didn’t mention which port was COM?, but COM? and COM9 should be your com0com pair. The TXD in the realterm echo tab should only start blinking when actual data is received through COM3, otherwise realterm has nothing to forward.
So to check if COM9 actually received data let replace the pc-link software by another realterm program. You can start a second realterm instance by right click on the realterm icon in your taskbar and select “realterm” when it starts it could give an error about the fact it can’t open a COM port, just ignore it. Ok, so now select in this second realterm instance the “Port” tab and open COM9, also you could set the “display as” to hex[spaces] if you want in the “display” tab such that you can verify the incoming data. It should look like 1x 2x 3x 4x 5x 6x 7x 8x 9x Ax Bx Cx Dx Ex where x is some value (which is not the same for each 1x 2x…) . So the connection path will look as follow:
[device | output ] → [input | program | output] → [input | program | output ]
[Mulitmeter | cable] → [COM3 | Realterm | COM8] → [COM9 | Realterm | data to window ]
It is important that COM8 and COM9 is your com pair from the com0com program. (I just choose COM8 and COM9). I think you could be right about the fact the pc-link software only accepts COM ports below 10, the software is shit so it doesn’t surprises me…
Let me know what data you received in your second realterm instance.
Here is a screenshot of Realterm showing my ports. Do you think there is a mistake ?
Port numbers look fine.
So your setup will be: open COM17 in the first Realterm application and select COM2 in the “echo port” tab (don’t forget to set the ‘echo on’ checkmark.
The second Realterm application should open port COM9. When you now set the multimeter in pc-link mode, your should see data flowing in both Realterm windows. Can you test this?
[device | output ] → [input | program | output] → [input | program | output ]
[Mulitmeter | cable] → [COM17 | Realterm | COM2] → [COM9 | Realterm | data to window ]
Only If you see data in both Realterm windows you can close the second Realterm application (the one where you opened COM9). Open now the pc-link software and open port COM9. If you don’t see data in the second Realterm window we need to investigate what went wrong.