Rigol DSO Trigger position Offset w/ AC coupled trggering , DS2000, MSO1000 - Page 1
Forum section: electronics / testgear

author: Teneyes
author_rank: Frequent Contributor
timestamp: November 24, 2014, 06:22:44 pm
content: Fixed in FW 00.03.03.01.00I discovered this DSO bug last year and it appears that it has not been corrected yet .It has been perpetuated on to the DS1074 series of DSOs also.The small bug is the displaying to the trigger position when using AC coupled triggeringThe Display of the waveform is NOT in the correct position.The waveform position is 50nSec to the left (early)The offset is a fixed amount of time 50nSecOn My DS2000 , with FW 00.03.01.00.04In order to demonstrate, in the animated displays below I am showing a frequency sweeping,As the frequency is changing , the trigger point along the waveform remains in the same positionYou can see the trigger point as the point on the waveform that is stationary on the displayWith these displays You can better see where the Trigger point isFor the displays the Trigger level is 0.0mVTrigger position should be at the Center of the displaybut it is offset 50 nsec to the left from the center for AC coupled triggeringthe 2 displays are:On 100ns/div the offset of 50nsec = 1/2 div , AC TriggeringOn 50ns/div the offset is 50nsec = 1 div , AC TriggeringMarmadhas confirmed that this occurs on the MSO1074Z , and aFix in Beta FWRf-loophas confirmed that this occurs on the DS1074Zretemitlum & HiassofThave confirmed that this occurs on the MSO2072AIf other owners of different models wish to confirm this bug . please add confirmation and send RIGOL a report so that it can be corrected when they fix the AC Jitter Bug(yes it is a Slow Dance)Edit,Yes I have resent this report to RIGOL China marketing & RIGOL NA

author: Teneyes
author_rank: Frequent Contributor
timestamp: November 24, 2014, 06:28:41 pm
content: Another display on the bug at a trigger level of 200 mv.the trigger point is up at the 200mv level but it is offset to the left 50nSec.

author: rf-loop
author_rank: Super Contributor
timestamp: November 24, 2014, 07:56:10 pm
content: Here is this time shit (>40ns) + jitter (~8ns p-p) with Trigger coupling ACModel DS1074ZBetween images onlytrigger couplingchange from DC to AC. (1. picture can see where is trig position)

author: Wim13
author_rank: Frequent Contributor
timestamp: November 24, 2014, 08:16:03 pm
content: Here are my test results , with a sqaure wave. Its clearly visible

author: i4004
author_rank: Regular Contributor
timestamp: November 24, 2014, 08:19:51 pm
content: teneyes how does this bug affect your measuring ie make your life harder?what do you gain if it's perfectly centered?and you don't have the ac trigger jitter problem, but have this trigger offset?could anyone start checking tek scopes for simillar stuff?i mean scrutinizing rigol thus far became quite exotic....

author: Teneyes
author_rank: Frequent Contributor
timestamp: November 26, 2014, 05:41:59 pm
content: Thank yourf-loopfor confirming this bug on your DS1074Z.Thank youWim13for showing that a fast square wave is an easy way to check for this Bug.Can anyone check on a DS2000A, MSO2000A. or DS4000 ?

author: rf-loop
author_rank: Super Contributor
timestamp: November 26, 2014, 06:11:26 pm
content: Quote from: Teneyes on November 26, 2014, 05:41:59 pmI did not confirm it in model DS1054Z, I have factory label DS1074Z in scope front.btw..When I make decision to buy one Rigol DS1074Z it was clear (least to me) that there is these not wanted trigger AC inaccuracies/bugs in this model serie (but also before buy decision I know there is not "5us problem" ) . When I think how severe these things are in my needs I did not think even 5 minutes if I buy or not buy.But, also, I make this decision in situation where I have lot of different scopes so also if I find that I really can not do with this Rigol some things, I can then use some other scope or other tools. But in this case I suddenly need one quite cheap 4 channel scope with some its special feature just for specified needs. And then also nice to know this model so I can some times give better pre sales customer care. Sometimes people need help and one important thing for reputation is give right recommendations after listen peoples needs - if they ask. Can not always think that what I sell is always best for customer. This kind of honest may walk back to me later - or not but still I do not loose anything.If I think, with my quite long experience, these two things, Trigger coupling AC trig jitter and trigger coupling AC over 40ns time shift related to trigger time position I can think they are not severe class fails what make this oscilloscope unusable. And specially if people know well his instrument limits then even less because when he know he can avoid possible mistakes.With digital oscilloscope it is quite rare case when I really need trigger coupling AC (in my use) so that it is only way to do. But sometimes handy.These are bugs what Rigol need try repair but they are not real fatal class bugs. (Including of course many other bugs and also UI need perhaps some small fixes)And I can say this from position where I sell other brand name products where Rigol is some kind of competitor.Every equipment have its pros and cons. Siglent, Owon, Rigol, Hantek etc all have least some strong argument and all these things are related also with price and most important is what user really need and want. In some cases I still use analog scope and even analog multimeter... but it is other story.Where from I purchased this Rigol. Of course from my old forum friend (Silcon Electronics in Czech Republic). His quality of customer service and after sales customer service is very excellent. I do not know a better service in Europe.

author: retemitlum
author_rank: Newbie
timestamp: November 26, 2014, 10:10:45 pm
content: Model number : MSO2072A "upgraded" to MSO2302ASoftware version : 00.03.00.SP1Hardware version : 2.2Test frequency : 100 kHz

author: HiassofT
author_rank: Newbie
timestamp: November 26, 2014, 10:59:33 pm
content: It's the same here on my MSO2072A, firmware 00.03.01, hardware version 2.2.Screenshots: 1.79MHz square wave (0-2.5V), DC-coupled. DC trigger level @50%/1.25V, AC trigger level at 0Vso long,Hias

author: mohandes
author_rank: Contributor
timestamp: December 02, 2014, 07:14:57 pm
content: hii want buy ds1074z.please tell us when these problem solve.thanks .

author: Teneyes
author_rank: Frequent Contributor
timestamp: December 10, 2014, 12:59:27 pm
content: On DS2000 , beta FW

author: Teneyes
author_rank: Frequent Contributor
timestamp: January 01, 2015, 12:14:59 am
content: This Bug is Fixedin this New Firmware for DS1000Z and MSO/DS2000Here

author: Electro Fan
author_rank: Super Contributor
timestamp: January 01, 2015, 10:14:36 am
content: The Rigol instruction pdf says:3. Press the power button on the front panel of the instrument. All of the buttons will light. At the same time press two or three times the Help key on the front panel. All buttons will unlight.4. If you now can see the Rigol Logo on the screen you failed to go into update mode. Please go back to step 3. If the screen stays black and the Single light will illuminate (as below in the picture) you can go ahead.Any suggestions on how to make step 3 work? (When I follow the step 3 process the scope just goes all the way to the normal boot up - I haven't reached step 4 yet.)Thanks, EF

author: Electro Fan
author_rank: Super Contributor
timestamp: January 01, 2015, 10:20:55 am
content: Ok, worse yet.....I have made it to the Rigol Logo screen - but the scope will no longer go to the normal boot up - and it won't seem to accept the "two or three times" press on the Help button. Kind of stuck in between here (step 3) and there (step 4).Thanks for any help.... EF

author: Electro Fan
author_rank: Super Contributor
timestamp: January 01, 2015, 10:37:39 am
content: An update:Turns out when the instructions say press the help button two or three times it means press the help button very fast two to three times. That caused the scope to proceed from the Logo Screen to a black screen and the Single light illuminated; then I inserted the USB stick and the CH1 button started flashing - all as the instructions indicated - that took a few minutes, then it went solid as described by the instructions. Then it says all the buttons on the front panel will be lit - which is where I am now except that the Clear and Auto buttons are not lit (but I'm betting those two aren't included in Rigol's definition of "all the buttons will be lit.")So, I'm going to assume I am done with step 7 and proceed to step 8 (Remove the USB drive and power cycle the instrument).Drum roll.....The system rebooted into a normal state and a check of the Utility / System Info says I now have 00.03.03.SP1Hey, hey - a bit nerve racking but we're back online.

author: Electro Fan
author_rank: Super Contributor
timestamp: January 01, 2015, 10:51:43 am
content: And the good news is that I previously had the same results as HiassofT (just before I updated the firmware I duplicated his settings and got the same jittery results) and now after the firmware update setting AC triggering brings no jitter - just a clean waveform.

author: Teneyes
author_rank: Frequent Contributor
timestamp: January 01, 2015, 11:28:09 am
content: @Electro FanAs I have been jumping around every FW from 00.00.01.00.05 to 01.03.03.00.02 , I have learned how to get the Boot going.For my body reaction timing, I find watching for theRUN/STOPto light then pressing the Help as fast as I can( right thumb is on 'Help' before pressing 'Power' on with Left Thumb, works every Time)Happy New Year

author: Electro Fan
author_rank: Super Contributor
timestamp: January 01, 2015, 11:44:17 am
content: Teneyes, Thanks - but I'm hoping not to do too many more firmware upgrades - for about 20 minutes I thought I might need to find the Rigol box to send it home to Rigol to have it brought back to lifeOn a related item - any chance that the new firmware improved signal fidelity in some respect? In looking at a few signals and circuits I have been using lately it seems like the scope is slightly more responsive and/or now showing details I hadn't previously seen - maybe it's just my imagination.... EF