Our New (possibly faulty) DS1054Z (and it's channel amplitude discrepancies) - Page 1
Forum section: electronics / beginners

author: adamboon
author_rank: Contributor
timestamp: June 16, 2016, 12:23:17 pm
content: Hi,So i read around this forum, interested in purchasing a new DSO to replace our ageing and unreliable 100MHz HP Scope. Settled on the Rigol DS1054z.We work mostly on Audio circuits, with tubes, opamps, FET's, BJT's and Tape Machines. Now I understand that most of these budget DSO's are 8 bit, and are far less accurate in the vertical than a good meter _BUT_ I'm pretty disappointed with the discrepancy in measurement between ch 1 and all the other channels on our new DS1054z.Measuring it’s own test point - the RMS values are giving me are 2.33 - 2.38 on channels 2, 3 & 4 (I’m totally fine with the 0.05 v variance) but ch 1 reports 2.00v (I’m not okay with a 0.38v, or just shy of 20%, variance). I have swapped the probes around, and the difference stays with the channel rather than the probe.I have "Self Calibrated” the unit twice (the first time only after about 15 mins of (warmup) on time, the second after about an hour).I also connected it to a 9V battery - the DC side seems to match up quite nicely.Quote from: My reply from the Australian Distributerso at 500mV / div i'm getting 1.46v on ch1 vs 1.75v on ch2 - this should be within 4v * 3% (4 x 0.03) = 0.12v? but is closer to three times that.I would be making serious measurements with an RMS meter - but I did expect the scope to be a little better than this. or at least let me apply a compensation to the channels to make the readings useful.Are my expectations too high? or have i got a dud? - I wouldn't even mind as much if the discrepancy was on ch's 3 or 4...

author: saturation
author_rank: Super Contributor
timestamp: June 16, 2016, 02:23:16 pm
content: I recall older post on this issue. A more recent post suggests variance is normal.https://www.eevblog.com/forum/testgear/ds1054z-voltage-differences-between-channel/msg907571/#msg907571Search the forum as "1054Z voltage" and choose a discussion relevant to you.A properly made scope will have all channels nearly identical and to spec, say 3% both for AC and DC , and particularly if you are exacting with the self calibration. Even if they are off calibration, all channels should drift close together <=3%. In actual measurement this often far less, < 1%.I have both a 1052e and a newer GDS 1054B with all channels identical in spec, both for measurement readings and function; I need them that way and I paid for that performance.

author: wraper
author_rank: Unknown
timestamp: June 16, 2016, 02:55:12 pm
content: Does not sound OK at all, if it was 5%, then maybe fine. But 20% is not fine for any oscilloscope. I had similar problem with Rigol Germany when my DM3068. They tried to prove that it's was performing OK, while it was certainly not. 6 months of brainfuck trying to deal with them.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 16, 2016, 03:06:18 pm
content: There is the trace display, and then there are the scope's calculated RMS measurements. As we know, the calculated RMS measurements can be quite bad, with the scope even able to report large RMS voltage values for channels that are _grounded_ and receiving no signal at all.I'm not sure if this "feature" came along with the latest firmware or not, as we didn't notice it until the SP2 firmware was in widespread use, and it's not possible to roll back to earlier firmware to check if the RMS errors are still there.One thing that is important to realize is that the scope uses the portion of the signal that is displayed onscreen for the calculated measurements. So for certain measurements, it makes a difference how many cycles or partial cycles are displayed. RMS can be one of those measurements. But still, one would like any errors due to partial cycles displayed, to be consistent across channels.It would be interesting to see the actual traces on adamboon's screen when the measurements disagree so much. Do the traces themselves also disagree by the same amount, or is this "just" the RMS measurement bug doing its thing?In any case, I suggest documenting the heck out of this problem, and if the scope is consistently shown to be out-of-spec, you can and should insist on a replacement under either the vendor's warranty or Rigol's factory warranty.

author: wraper
author_rank: Unknown
timestamp: June 16, 2016, 03:24:39 pm
content: Quote from: adamboon on June 16, 2016, 12:23:17 pmWhat is the actual signal you are measuring, frequency? Have you properly adjusted probe compensation on particular channel?it's there, should read more carefully.

author: wraper
author_rank: Unknown
timestamp: June 16, 2016, 03:28:52 pm
content: Quote from: alsetalokin4017 on June 16, 2016, 03:06:18 pmThis seems like a very obvious firmware bug, nothing else. Waveform certainly does not show anything like this being even remotely possible.

author: wraper
author_rank: Unknown
timestamp: June 16, 2016, 03:53:13 pm
content: BTW what about Vpp measurment, actual signal amplitude shown on the dispay? Maybe you should make a screenshot and post it here.

author: adamboon
author_rank: Contributor
timestamp: June 16, 2016, 09:31:21 pm
content: Thanks for your helpful reply. One question on the below comment:Quote from: saturation on June 16, 2016, 02:23:16 pmIs the (older, 2ch) Rigol 1052e a better, more accurate or more reliable piece than the 1054z?I guess the same question for the Instek. I went with the 1054z because it seemed like it was getting lot of love on this forum. Also I liked that I got it through an Australian Distributer. I was also looking at Hantek, Siglent and USB Picoscope models. I don't need 4 channels, or fast speeds.

author: adamboon
author_rank: Contributor
timestamp: June 16, 2016, 09:34:17 pm
content: Attached is the original photo i snapped (Rigol's "Auto" settings, i tried it with the probes connected one way, then plugged them in backwards to check the problem wasn't a probe).Second pic is manually changing the V/div as suggested by the distributer. I _MAY_ have fiddled the fine vertical amplitude adjust (I was playing with it to see if it affected the Vrms value - it doesn't).I will check the Vpp and Vmax this morning and report back.Thanks for all your helpful and patient replies.

author: wraper
author_rank: Unknown
timestamp: June 16, 2016, 10:39:34 pm
content: I would say it's a firmware bug, not actual hardware issue because waveform amplitudes look exactly the same. What happens if you try to disable all other channels? Try to update the software and/or reset it to the factory settings. Try this reset method too:Quote

author: adamboon
author_rank: Contributor
timestamp: June 16, 2016, 11:49:56 pm
content: Wraper, I think your onto somthing. Vpp is within .02vThe unit reports Version00.04.03.SP2And board version0.1.4I'll try the reset when I'm back in front of the scope. Thanks all for all your help!

author: Meka77 wd
author_rank: Contributor
timestamp: June 17, 2016, 09:48:34 am
content: Hi everyone... This is for adamboon. I am waiting a solution about 6 months for this and other concerning problems. And our local rigol dealer does not answer my phone calls anymore. Before 4.03.02.03 firmware everything working fine and fast for me anyways. I think main issue is devices ability to flash former firmware, because accidents may happen in factory when developing or debugging on new firmware. Then user choose return to former working firmware, like cellphohe or pc etc. I actually beg them for return to sp1 firmware because i am using this device for work. But nothing so far and everyone seems happy with this and not complainig about it to rigol. I have 4 rigol scopes at my home right now, my first ds5022m still works as expected, ds1052e at 100mhz works as expected, ds2000a at 300mhz works nicely and you can flash whatever firmware ver. you want. Last this 1054z sitting over couch about 5 months and still have a useless warranty. Sorry for my bad english and thank you for your time.https://www.eevblog.com/forum/testgear/ds1054z-issue/msg919023/#msg919023

author: wraper
author_rank: Unknown
timestamp: June 17, 2016, 10:18:41 am
content: I have an idea. I guess you always trigger on CH1, what happens if you trigger on some another channel, or using other channels one by one with all other disabled? BTW, it seems that actually CH1 is showing correct Vrms but all other channels are lying.Edit: as Meka77 wd said, this seems to be the same firmware bug, read that tread. Digital crosstalk, do Rigol verify their firmware at all?

author: saturation
author_rank: Super Contributor
timestamp: June 17, 2016, 12:17:30 pm
content: Hi I don't own a Z so I can't compare.The 1052e performs per its data sheet and what bugs it had or remains are not critical, they don't impact measuring capabilities; e.g. my unit may lock up if I hot swap a USB drive when triggering, the rotary encoders sometimes get too sensitive, type issues.The c2008-2009 1000e has had time to mature. But even on initial release there were no critical bugs and brought Rigol's fame for its price performance. A variant of the 1000e series was rebadged for Agilent with the Rigol version having slightly more features, such as memory.Instek as a company makes reliable devices [I've used them off/on for 30+ years] but they cost more and have less features for price, if you compare spec sheets. But it lives up to its spec sheet and its quality is consistent.The 1.5 year old GDS 2000E series had bugs on release but none critical, you can read of the genesis of issues in eevblog forum reviews. The lower end GDS 1000B series is ~ 1 yr old and had no critical bugs, actually no bugs with my unit OOB and with current firmware. Because of the new technology used in 2000E and 1000B models, they are lower priced too to come close to the price performance of Rigol equivalent models, but with Instek reputation.I suggest you get a scope from a local dealer, so you can test and exchange whichever until one works for you. What we see in eevblog's international forum is take home prices for models as well as availability vary with country. If you buy mail order international you could save but if things go wrong and its warranty not honored locally, it can cost a lot to ship back internationally.Last cautious words: over the years of reading eevblog forum chatter, the quality control of Rigol has taken a step down in entry level devices of its product line: the Z, the 1000e series [ newer production] and the DP 832 PSU, to name a few. So test it thoroughly after receipt within the window you can return it to the dealership for an exchange.Quote from: adamboon on June 16, 2016, 09:31:21 pm

author: wraper
author_rank: Unknown
timestamp: June 17, 2016, 12:47:38 pm
content: Quote from: adamboon on June 16, 2016, 09:31:21 pmI have multiple pieces of Rigol equipment and certainly regret buying their DM3068 multimeter. Kind of fine with DG4062 signal gen but as I don't use it too much, have not stumbled into the bugs which are there according to what people write. DS2072 scope didn't make me feel very happy about the purchase either, mostly because of hanging and painful controls (as example pushable intensity/menu selection encoder, pain in the ass. Never can select what you want). But at the time there wasn't anything comparable from Instek to replace my old trusty Instek GDS-1152A (similar to Rigol DS1000E). Recently I bought Instek GDS-2204E and it is like day and night compared to Rigol. If you are fine without hacking the scope and don't need getting serial decoders for free by doing that (which I'm sure most people don't need but say it as 100% argument why you must buy it and then hack), GDS-1054B is much better deal, and the most of all it can be trusted, cost even a bit lower than DS1054Z.

author: adamboon
author_rank: Contributor
timestamp: June 20, 2016, 07:57:28 am
content: Oh I wish I would have purchased the instek... I can't see them in Australia though - so i'd need to ship it from overseas. I'm torn between sticking with the 1054z and hoping Rigol get their act together. But I might ask if I can send it back and look into the Instek. It will probably depend on if the RMS issues os resolved by the reset - haven't had a chance to try it yet.

author: saturation
author_rank: Super Contributor
timestamp: June 20, 2016, 02:37:30 pm
content: Perusing google I see several GWInstek dealers in Oz but the model is not listed on the website, can't hurt to ask them. As always, local dealers can provide support; a demo was sent to Dave back for the 11/2015 review so maybe there is a preferred dealer.There is one side issue: if your workplace requires "NRTL equivalent in Australia recognized" EMC and safety certification, this device is only CE.Quote from: adamboon on June 20, 2016, 07:57:28 am

author: adamboon
author_rank: Contributor
timestamp: June 22, 2016, 12:22:06 am
content: So I've done a bit ok poking around, and everything except the Vrms seems to okay. It is the rms issue as outlined in the other thread. there is another function Vrmsp which is also called Pers. VrmsI'm taking a wild guess that this is Persistent RMS - But I don't know what that means. It does seems to math it out correctly though.Are there any other "Issues" I should be aware of with the 1054z? The distributer is going to call me back soon and I'm going to make some noise about the RMS issue and also request that I send it back and get a GDS-1054B if possible. Mostly because of how many other bugs and issues may be in the machine that I am yet to discover - if I wanted an unreliable 'scope I could just use my old analog HP

author: saturation
author_rank: Super Contributor
timestamp: June 22, 2016, 10:08:26 am
content: Here's an updated list of bugs, it would be a great service to all if you can confirm it:https://www.eevblog.com/forum/testgear/new-rigol-ds1054z-oscilloscope/msg966871/#msg966871Quote from: adamboon on June 22, 2016, 12:22:06 am

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 22, 2016, 12:58:02 pm
content: Quote from: adamboon on June 22, 2016, 12:22:06 amIf you are talking about the Rigol DS1054z, the measurement is actually "Per.Vrms" and it stands for "Period RMS". If you push the Help button at the top right of the control panel, then press the "Per.Vrms" hotkey in the Measurements area on the left side of the screen, you will see what the scope means by this function. It is the RMS value within a single period. The normal "Vrms" measurement is the RMS value across the whole screen display.The scope's "Help" function is a nice feature which will give more-or-less thorough explanations of just about any hotkey or control panel knob or button.QuoteThe various other issues with the Rigol DS1054z have been discussed elsewhere in the forum. The one that bothers me the most at present is the Measurements Fail bug that causes all Measurements to simply stop working after a random time period, when 3 or 4 channels are turned on and a Math trace is displayed, requiring a power-cycle reboot to reestablish Measurements working.

author: adamboon
author_rank: Contributor
timestamp: June 24, 2016, 01:29:19 pm
content: I spoke with John South from emona, where I purchased the scope. He has verified the (Vrms) fault and is working on it with Rigol.He has been very good to deal with. I think I am happy again to have paid up and waited to get local support.I'll keep y'all posted with the details.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: June 24, 2016, 04:28:52 pm
content: Quote from: adamboon on June 24, 2016, 01:29:19 pmThanks for keeping the pressure on.I wonder if you or John South have encountered this Measurements Fail bug as shown in the video below yet. I did report this one to Rigol USA six or seven months ago, they said they were indeed able to reproduce it on their lab scopes, but that's the last "official" word I've heard of it.

author: bitseeker
author_rank: Super Contributor
timestamp: June 24, 2016, 10:28:09 pm
content: Quote from: adamboon on June 24, 2016, 01:29:19 pmThat's great news! Hopefully, a fix for that and the lockup during Math functions (already reproduced by Rigol) will be forthcoming. And that "Pluses" spelling error (talk about an easy fix). Anyway, I'll try not to get my hopes up, but it sure would be nice.You can do it, Rigol.

author: adamboon
author_rank: Contributor
timestamp: June 28, 2016, 04:54:13 am
content: John from Emona just emailed me this update:Quote from: John SouthI have found them (emona) great to deal with so far - and will stick with the Rigol (and await the update).

author: bitseeker
author_rank: Super Contributor
timestamp: June 28, 2016, 05:16:50 am
content: Thanks for the great news, Adam. And thanks to John at Emona for the great customer service. Maybe Rigol was already going to release an update, maybe not. Either way, it doesn't hurt to have more vendors influence change.

author: Fungus
author_rank: Super Contributor
timestamp: June 29, 2016, 04:23:36 am
content: Quote from: bitseeker on June 28, 2016, 05:16:50 amIt's overdue.During the first year they released an update every quarter (more or less). It's been over six months since the last one.

author: bitseeker
author_rank: Super Contributor
timestamp: June 29, 2016, 05:26:00 am
content: Yeah, back in October.

author: adamboon
author_rank: Contributor
timestamp: July 20, 2016, 03:21:04 am
content: Just got an email from John:Quote from: John SouthThe Changeling Indicates:Quote from: Release Notes

author: bitseeker
author_rank: Super Contributor
timestamp: July 20, 2016, 05:05:32 am
content: Yep, no mention of the RMS problem. Some reports from other forum members are that the "Pluses" typo hasn't even been fixed.Have you tried the new firmware? Did it take care of the issues you're currently encountering?

author: adamboon
author_rank: Contributor
timestamp: July 20, 2016, 12:00:44 pm
content: I loaded the new firmware and re-did the self-cal but didn't get a chance to check if the problem was solved. Will check it as soon as I can. I had been using VpRMS though (in previous firmware), it works okay.

author: adamboon
author_rank: Contributor
timestamp: July 28, 2016, 10:16:00 am
content: RMS bug still exists...

author: bitseeker
author_rank: Super Contributor
timestamp: July 28, 2016, 10:40:17 pm
content: Yes, there's a very lively discussion about the RMS bug in the BIG thread. It seems the other problems (math, freeze, etc.) are fixed, though.Perhaps sending feedback to John will be helpful, so he knows it's still an outstanding issue.

author: John at the Falls
author_rank: Contributor
timestamp: March 27, 2017, 01:31:33 am
content: Quote from: wraper on June 17, 2016, 12:47:38 pmGreat advice about alternatives to the Rigol scope. I think anyone considering the Rigol should also look at the GW Instek line. I have been studying my new 1054 for the past 2 days and am happy with it. I do not feel comfortable with the hack but I purchased this based on features per dollar when I actually am not tightly constrained by the cost. I am just using this to build CNC equipment. But I thought it would be nice to have all the features just in case."Features per dollar" and "just in case" are not the best reason to make a purchasing decision.I think when one knows exactly what they are working on, it is easier to make a good purchase without overspending on features. But I bought this scope because I do not know exactly what I am working on and need to learn.