About the trigger, can I somehow trigger Ch1 and Ch2 seperately? Isn't that a sort of common feature? My old 1970 scope could do that, anyways
It's not a big problem because the memory depth is so huge, but it would still be nice in some situations.
From the above, I would conclude that dead times only happen after trigger events. So, if there's a one-time event you set the edge trigger up for, and if (sic) you set the trigger to Normal mode (not Auto), you'll capture it for sure. Is that correct?
Oh also, the DS2202 seems to display more than one captured waveform per screen update, even with Min persistence time set. "Min" apparently means "all waveforms captured since the last screen refresh"... which is just fine. It implies, however, that pressing STOP while the scope is in T'D or AUTO state will not have the same result as pressing SINGLE, then FORCE (or waiting for a trigger event), since the former might display more than one waveform on the screen.
Hi!
Since recently I also own a DS2000 series scope (the 200MHz version) and I have some questions and comments too.
Then, some things that confuse me.
In the drawings, the probes that come with the scope have two adjustment screws, for LF / HF or so, one on the plug and one on the probe itself. Mine only have a screw on the plug and the hole on the probe is filled with plastic stuff (but the hole can be seen clearly). Is that normal?
Also about the probes, the hooktip accessoires don't stick to the probes well, they very easily slip off a bit and then you're confused why you don't measure anything. Am I just too stupid to mount them (you just need to push them over the probe front, right?) or is this really a problem?
About the trigger, can I somehow trigger Ch1 and Ch2 seperately? Isn't that a sort of common feature? My old 1970 scope could do that, anyways
It's not a big problem because the memory depth is so huge, but it would still be nice in some situations.
Then, why did Rigol decide not to have a 50 Ohm input on the scope? I found that many of the scopes on the market don't have it. Is it because it's a bit easy to destroy with high-power input?
Anyways, if I plug a BNC T piece directly into the scope input, and terminate one end with a 50 ohm load, and plug my 50 ohm signal into the other, that will basically be a 50 ohm input with still accurate voltage measurements; correct?
Greetings,
Sven
And the probes are oke for frequencies to 30 Mhz, and for pulse signals. For hihger frequencies you have to
use terminated cables. See also former posts.
That is correct, thats why you have also special probes and active probes. If you want to do lab measurements
then you have to think about all these things. these cable reflections has so many influences.
I have worked for a cerfication calibration company, and before you were allowed to do any measuremts, you had
to follow several courses for several months. Anyone can read a display, but only a few knows what they measure.
QuoteFrom the above, I would conclude that dead times only happen after trigger events. So, if there's a one-time event you set the edge trigger up for, and if (sic) you set the trigger to Normal mode (not Auto), you'll capture it for sure. Is that correct?
Yes, in principle, the 'dead time' extends from the trigger moment. But for fast signals, you might have to consider the hold-off as well. The trigger system is not activated until a specified amount of samples are measured after starting the measurement (the trigger hold-off). When the input signal meets the trigger requirements during the trigger hold-off period, this will not generate a trigger and the system will remain sampling pre-samples. After the trigger hold-off has passed, at the first occasion that the trigger conditions are met, the system will start measuring post samples.
QuoteOh also, the DS2202 seems to display more than one captured waveform per screen update, even with Min persistence time set. "Min" apparently means "all waveforms captured since the last screen refresh"... which is just fine. It implies, however, that pressing STOP while the scope is in T'D or AUTO state will not have the same result as pressing SINGLE, then FORCE (or waiting for a trigger event), since the former might display more than one waveform on the screen.
Yes, but there can actually be only ONE final waveform in the sample memory eventually, so even though you see the contents of the waveform buffer (> 1 waveform) when you STOP the DSO - as soon as you change the horizontal or vertical scale, you see the display 'snap' to the last waveform captured.
And yes about the 50 ohms it is not correct..., the BNC connector has not a high impedance for higher frequencies,
so the voltage on the BNC connector is not wath it is. Mine has 1 Mohm and 18 pf input, and also some inductance.
Even if you have a 50 ohm terminator on the input, the BNC connector has a complex impedance, which gives
wrong readings and also standing waves, as you can see on your plot.
Active probe Rigol RP7150 Fits for Rigol Series 4000, 6000 costs 3268 Eur. There is no for DS2000.
Okay, I guess this is to have a consistent amounts of samples available for the user to scroll through before the trigger ... triggers.
Once the system is running, this will basically just add to the dead time tough, won't it? *
Aah, alright, interesting. So they probably just use a screen buffer and draw all captured waveforms into it, and then 30 times per second (or whatever the screen refresh rate is), they swap the buffer to the screen and clear it? That sounds logical. Thanks for explaining!
* That "iff" you corrected to "if" was not a typo, it was borrowed from formal logic
Quote* That "iff" you corrected to "if" was not a typo, it was borrowed from formal logic
Yes, of course - I knew this - but the weird thing is that I don't remember processing it OR correcting the writing I must have done that without even thinking about it.
But then looking back to your original statement as logic:
"So, if there's a one-time event you set the edge trigger up for, and iff (sic) you set the trigger to Normal mode (not Auto), you'll capture it for sure."
is NOT true - because you can also set the trigger to Single mode with the same outcome
This is problematic, because it does not appear always on every saving and loading.
@scummos
BTW, I don't know how much of this exponentially-growing thread you've managed to cover, but in case you missed this post regarding the wfrm/s rate of the scope - it might be of interest to you. It shows that the 20ns timebase scale is the optimal one to use (if possible) when glitch-hunting (i.e. smallest amount of dead time).
Is there a difference if you immediately reload after saving, or if you perform some additional measurements in between? From the descriptions, it sounds like the scope draws whatever is in the sample memory instead of the missing data, and if you just do a save and reload, chances are the original data is still there.
Since you (marmad) are the main contributor to this thread (and several other DS2000 related threads on EEV forums), perhaps you might consider starting a webpage (or wiki) containing the collected wisdom on this subject. Perhaps Dave might help out with space and a reasonably well known domain name.
@scummos
BTW, I don't know how much of this exponentially-growing thread you've managed to cover, but in case you missed this post regarding the wfrm/s rate of the scope - it might be of interest to you. It shows that the 20ns timebase scale is the optimal one to use (if possible) when glitch-hunting (i.e. smallest amount of dead time).
but when push to full scale it drops to 38100 , so the vertical scale has also influence.
BTW, I don't know how much of this exponentially-growing thread you've managed to cover, but in case you missed this post regarding the wfrm/s rate of the scope - it might be of interest to you. It shows that the 20ns timebase scale is the optimal one to use (if possible) when glitch-hunting (i.e. smallest amount of dead time).
BTW, in the interest of pushing the software I'm writing on more owners it takes the Rigol 15 seconds to write a PNG file to a USB stick - and then, of course, there's the time needed to transfer the stick to a computer and read the file. It takes the Rigol UltraVision Utilities 2.3 seconds (using USB) to transfer the data to the PC and save it
BTW, in the interest of pushing the software I'm writing on more owners it takes the Rigol 15 seconds to write a PNG file to a USB stick - and then, of course, there's the time needed to transfer the stick to a computer and read the file. It takes the Rigol UltraVision Utilities 2.3 seconds (using USB) to transfer the data to the PC and save it
DS2000 series owners check your heat sink clips!
Thanks for reporting this Martin. Unfortunately there's no easy way to check them without taking off that pesky sticker - aside from shaking the device - which might cause the problem.
I've never been a big fan of this method of spring retention - it's always seemed a little dubious to me. I've had them come off on three different motherboards over the years.
Not tested yet - the parameters of this bug are still unknown - and I haven't had the time to do a thorough investigation. Perhaps you'd like to discover them?
Are using the Lan or the USB interface.., ?
I have only the IVI drivers loaded yet, could not download the Ultra Sigma software, the Rigol site is so slow.
Does your software run without the Rigol Ultra Sigma..?