Siglent SPD3303D series bug - Page 1
Forum section: electronics / testgear

author: monz
author_rank: Contributor
timestamp: December 27, 2014, 07:46:48 am
content: Hello, first post here. I recently bought a new Siglent SPD3303D power supply and there seems to be an issue with its series mode.Short version:It seems like a software bug where it's incorrectly displaying channel 1's current on both meters in series mode. It seems like it's assuming that the load will be across both supplies, in which case the current would be equal, but since there is a common connection, this this cannot be assumed. It works as expected when the series connections are made externally.Anyone with this unit able to reproduce?Details:This power supply has 3 independent/isolated supplies. Its two variable power supplies can be placed in series or parallel via buttons on the front panel - relays inside do the necessary switching.All works as expected, except for the current meters in series mode.In series mode the positive side of the channel 1 supply is connected internally to the negative of the channel 2 supply, forming a common point and placing them in series. Channel 1 then becomes a negative supply and positive on channel 2 relative to the common point. A load can be placed across both or two loads, one across the negative side and common and another across positive and common.Each supply has a current and voltage meter. I would expect the current to be displayed for each side independently while in series mode since the loads between either side and common will not be exactly the same and to only see the same current on both when there is a load across both with no common connection.What's occurring is, when in series mode, if I place a load across channel 1 (negative side and common) and no load on channel 2 (positive side and common), the same current reading is displayed for both channels. I would expect to only see current on the channel 1 meter and 0A on channel 2 - since nothing is across channel 2.If I place the load across channel 2 (positive side and common) and nothing on the left side, the current meter reads 0 (load is receiving power).When not in series mode (with channels operating independent), both meters work as expected.In parallel mode both meters also work as expected, the current is divided equally between the two channels.If I wire the two in series externally, everything works as expected.Software version is 1.01.01.01.06Hardware V1.1I cannot get the firmware to update, it says it's not compatible or similar message when attempting to update from the EasyPower software.I'll attach photos to show the arrangement. It may be hard to see but the right channel's (channel 2) negative (black) terminal is labled COM for the series mode. Note same current on both channels with only load on channel 1 and no current with load on channel 2.

author: tautech
author_rank: Super Contributor
timestamp: December 27, 2014, 10:07:42 am
content: Welcome to the forummonz.May I suggest you place a link to this thread for Siglent to see when they are back at work next week.Place it in this thread:https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/Sorry I do not have the SPD3303D to attempt to replicate your problem, interesting as it is.Any firmware update file should be sourced from the Siglent website not from the supplied CD.This software is for PC connection, not firmware update.Here is the latest firmware:http://www.siglent.com/ENs/gjjrj-xq.aspx?id=874&tid=15It seems only a few months old, but I have no idea if it will address your problem.

author: rf-loop
author_rank: Super Contributor
timestamp: December 27, 2014, 11:06:55 am
content: Here is attached how User manual give instructions.Are there problems after you use it following instructions in User manual?If your current is 1A (and CH1/2 series) it flows via both output stages and both show correctly 1A.(Perhaps Siglent need add one relay for connect CH1+ and CH2- totally to N.C. state in series mode. Then it do matter if user try connect his load randomly/accidentally where ever)I do not know reason why there is common mark on the front panel for series connection. What "common"? and I do not have this SPD for check how it is and I do not have schematics for this.(as marginal note:I do not understand what all chinese manufacturers afraid and they do not give full component level service schematics. Look old Tek and HP, there is all, open for everyone and it was also when these was active in production, not only afterwards. Copycats do not need schematics.But good after sales customer care need, urgently, for every model and version. I recommend Siglent is first chinese manufacturer who is enough wise for do this. Effect is only positive, and all parties can only win in final. Question is how to protect from copycats. Secret is manufacturing quality and pre- and after sales customer care quality. It can not easy copy.)

author: monz
author_rank: Contributor
timestamp: December 27, 2014, 07:55:51 pm
content: Thanks for the replies.I'll check out the Siglent thread. The software that controls it from a PC is also used to to update the firmware using the file that was linked above. It says there's a version mismatch or similar. I've tried a few times.Common is the point of connection between the CH1 and CH2 supplies. This becomes the circuit ground in cases needed a +/- power supply.Connection is like this when the series button is pressed, if this makes sense:(-) (+)--common--(-) (+)+ on CH1 is connected to - on CH2.So you can get CH1 and CH2 added together across them, in which case current would be the same. Or a negative voltage between CH1 and common and positive between channel 2 and common, currents would not be same. The manual doesn't show this specifically, but this is what the common connection provides and is how they're connected, the manual is not very detailed and full of errors.I would expect both meters to always measure the actual currents in either side, this occurs when operating independently and connected together externally.The manual doesn't go in to much detail. Step 3 is actually incorrect as CH2 just beeps when knob is turned is turned in series mode, the settings are set form CH1 for both (2 outputs whatever 1 is in this mode).I think the software is assuming that connection would only ever be connected across both as pictured in the manual, and never between either side and common. This can't be assumed. Common can't be seen in the manual picture, its under CH2 - covered by binding post.I agree, a schematic would be helpful as it helps understand any limitations. I've not looked inside yet.

author: rf-loop
author_rank: Super Contributor
timestamp: December 28, 2014, 09:34:55 am
content: Quote from: monz on December 27, 2014, 07:55:51 pmI know exactly what is common in normal double sided power supply.I have not this model for test at this time. Manual and datasheet they are so poor that really can not say anything exatly. It need this unit for study and exercise how it works. Personally I do not accept this level of User Manuals at all. Better than nothing but just toy class. This (User Manuals, Datasheets, Service Manuals etc) is area where Siglent and many Chinese manufacturers really need develop lot of)After trying read manual and datasheet many times I have only my personal opinion how I think it works.(I leave CH3 out from my answer)There 2 independent floating power supply. Both 0-30V.If need double sided power supply with separate adjustments for both sides (-|0|+) ) you can do it simply externally. (connect CH1 + to CH2 - and this is your "common" (0)) There you can separately adjust negative and positive side voltage and current limit.Manual: "In the series mode, CH1 and CH2 are linked internally intoone channel....and theoutput voltage value is twicecompared with that of single channel."It do not talk anything about double sided (-|0|+).Data sheet: Series and parallel function allowstwo channel combined intoone output....If need single output (one channel) 0~60V power supply you use "series" mode. You connect load to between CH1 - and CH2 + terminals. Control is CH1.This single supply output rating is 0~60V/0~3A(also this can do externally with independent mode but now you need use both channels adjustments)If need single output 0~30V but more than 3A current you use "parallel" mode. You connect load to between CH1 - and CH1 + terminals. Control is CH1.This single supply output rating is 0~30V/0~6AIn manual there is note about CC in this mode.I hope Siglent write acceptable level User Manual so that alone with manual you know exatly what it do and what not and every exeptions and every limit in all things and using combinations. Now it need this equipment for study how it work.How user manuals need write. There is lot of examples and materials for free study, free available. Example olderHP(/Agilent/Keyshit) and older other well known high level brands power supplies User manuals and Service Manuals and Programming manuals.If manuals are shit:they are perhaps first contact with potential customer who first try read carefully manuals and datasheets before make decision to buy. Do you know what happend to peoples if in first meeting first minutes something fails totally. This can not repair never. It is game over. If people see shit manual he put "shit stamp" to this equipment and go to some other.But even more bad. If people read datasheets and manuals and then buy. If he after then find that manuals have been bullshit and datasheets have not been datasheet but they have been ads what only have told nice things giving wrong imagine about functions and after this disappoint, he feels scammed and you do not have so much value you can get this customer back. Also poor rating is spreading everywhere.If some give good rating, perhaps he think only alone with silence or just someone may heard it.

author: monz
author_rank: Contributor
timestamp: December 29, 2014, 06:03:25 am
content: I do see in the manual where it does say they'll be linked in to one channel and it shows connection across them. But it does label the common connection as such, which implies it's ok to use it as a +/- supply - and I'd expect voltage/current to be measured for each half. I think the explanation was omitted form the manual. Photo attached of series connection on front panel showing common point in series mode.It seems if if it was only intended only to have the load across both and act as one supply (with nothing between common and either end), they wouldn't provide a connection labeled "com." Since there are meters on each side, I'd expect them to indicate for each side.Additionally the volt meter on the positive side when in series mode (ch2) does function independently, it drops as expected when the positive side is shorted to com (and the constant current led turns on as expected), the ch2 current meter continues to show 0 when shorted.And when the negative side is shorted (ch1), voltage is correctly indicated, the same current again shows on both sides (including the side with no load).It just doesn't seem correct. Maybe I'm missing something obvious or thinking incorrectly. Maybe something beyond connecting the two supplies together is happening in the hardware when the series button is pressed. I'm envisioning a volt meter on each side and a current meter in series with each side and the two connected with a relay (confirmed continuity in series mode). A schematic would be helpful. I normally open things up and investigate, but I don't want to void the warranty.Photos attached to show the positive side (ch2) in series mode correctly measuring voltage and not current. Also connection diagram printed below binding posts.

author: rf-loop
author_rank: Super Contributor
timestamp: December 29, 2014, 11:27:03 am
content: After around 2 weeks also I can do some real lab tests (and also more) how it really works etc. (also perhaps something about its HW).Im also interest how well its regualtion works in different loading situations and step responses.

author: Siglent
author_rank: Regular Contributor
timestamp: January 04, 2015, 05:46:53 am
content: there is a new firmware nowhttp://www.siglent.com/2014EnglishWebsite/Firmware&Software/Firmware/spd3303d_V100R001B01D01P06r2.rar

author: Zbig
author_rank: Frequent Contributor
timestamp: January 06, 2015, 08:22:05 pm
content: Quote from: Siglent on January 04, 2015, 05:46:53 amHi Siglent,See below, what this firmware update has done to my SPD3303S FW:1.01.01.01.03R1 HW:1.0 (well, it somehow got magically "upgraded" to 1.2 after applying that). Any advice?EDIT:I meant SPD3303S firmware update (1.01.01.01.06R2) listed for this exact model on the Siglent website. I haven't applied SPD3303D update to the SPD3303S model.EDIT_2 (dry joke time):At first I thought it's only for Australia but then double-checked the website and nope, it clearly said Europe.

author: devanno
author_rank: Regular Contributor
timestamp: January 06, 2015, 09:04:08 pm
content: QuoteGlad I wasn't drinking coffee when I saw that image in light of your comment... :::sputter::: !!!

author: Siglent
author_rank: Regular Contributor
timestamp: January 08, 2015, 08:01:07 am
content: Quote from: Zbig on January 06, 2015, 08:22:05 pmWe are sorry for our careless mistake. your unit is not compatible to the latest firmware (1.01.01.01.06R2).A temporary solution is to downgrade to the 1.01.01.01.03R1 version.For SPD3303Shttp://siglentamerica.com/USA_website_2014/Firmware&Software/firmware/SPD3303S_V100R001B01D01P03R1.rarFor SPD3303D[url=http://siglentamerica.com/USA_website_2014/Firmware&Software/firmware/SPD3303D_V100R001B01D01P03R1.rar]We will release a new firmware to adapt your hardware later.

author: rf-loop
author_rank: Super Contributor
timestamp: January 08, 2015, 09:40:14 am
content: Quote from: Siglent on January 08, 2015, 08:01:07 amPlease, @Siglent, urgently add information how peoples can check exactly what version is compatible.It need read as Important note in all official download sides. ( what is compatibe FW version with different HW version and how to check it)

author: Zbig
author_rank: Frequent Contributor
timestamp: January 08, 2015, 12:34:19 pm
content: Quote from: Siglent on January 08, 2015, 08:01:07 amThat's okay, it happens. Thank you for providing my original firmware. I'm looking forward for the new versions compatible with my hardware version, thank you for that.

author: Salas
author_rank: Frequent Contributor
timestamp: June 18, 2015, 02:22:13 pm
content: Has the series bug been solved with new firmware yet? Thanks.

author: tautech
author_rank: Super Contributor
timestamp: June 19, 2015, 02:09:58 am
content: I'm not sure if the series bug even exists?I've just got a "C" model in stock as there has been some inquiries for them.Inseries modeit displays the current drawn correctly and displays the series connected voltage HALVED.Both Ch1 and Ch2 displays, V & A are active.This is described in the manual and while not perfect, it is as expected if you RTFM.Ch1 is the master channel in series mode, it controls both channels but only displays half the series voltage.If Ch2 was to display 000 and Ch1 the true voltage, it would be better than present.Personally I'd like to see inseries mode, ONLY ONE DISPLAY OPERATIVE, indicating the true voltage output(not halved) and a single current meter.As there is a soft key membrane UI for all selection parameters, one wonders if HW can support this change and only new FW is needed to make it happen.Siglent might expect howls of protest changing the UI dramatically, but would it not be for the better?

author: Salas
author_rank: Frequent Contributor
timestamp: June 19, 2015, 12:09:25 pm
content: Quote from: tautech on June 19, 2015, 02:09:58 amFirst to know in a symmetrical rails powering situation with a center GND tap is what voltage and current happens to each power section individually. Symmetrical voltage rails DUTs do not guarantee symmetrical current & power draw. Showing the totals across channels is welcome as secondary displayed information not to make the summations mentally.The C model is the cheapest one with LED displays, right? That one does not have the display to present extras so it does the basic right thing I guess. Its not clear if the D & S models with the color screens do the same by now though.

author: Salas
author_rank: Frequent Contributor
timestamp: June 19, 2015, 01:03:41 pm
content: P.S. Since you got the C model in hand tautech, would you do a small easy test to enlighten us please? Load the two sections with different resistors say 100 Ohm & 150 Ohm. Or something like that. Press series and see if it does display two same voltages and two different current draws indeed.

author: tautech
author_rank: Super Contributor
timestamp: June 20, 2015, 10:39:03 am
content: Quote from: Salas on June 19, 2015, 01:03:41 pmTo appease you I have done your test:InSeries modewithloads on both main channel outputs, half the nominal voltage is displayed on both channels(as expected, but should be changed), but the current draw of channel 1 is displayed on both channels.THIS IS NOT HOWSERIES MODEIS INTENDED TO BE USEDIn the Quick Start guides, Page 20 of all versions of SPD3303 (C, D and S) clearly explains theSeries modeoutput connections:QuoteAlso operation description forSeries modeon all models is identical.Series modeallows for asingle channel outputof up to 60V and 3 Amps.C version Manual:http://www.siglent.com/2014EnglishWebsite/Documents/UserManual/SPD3000%20LED%20User%20Manual%EF%BC%88V1.0%EF%BC%89.pdfD & S Manual:http://www.siglentamerica.com/Uploadfile/file/20140926/SPD3000_UserManual_EN.pdfCurrent FW forSeries modehas all these models showing the same nominal voltage on both channels(that must be doubled to match real output) and TOTAL actual load current replicated on both displays.This is not good and confusion will arise, inSeries modeIMHO only one channel display should be active.One channel display only should indicate therealvoltage and current inSeries mode.000 or ---- displayed for the inactive channel inSeries modewould be better than it is at present.Siglent should change this......

author: Salas
author_rank: Frequent Contributor
timestamp: June 20, 2015, 04:35:22 pm
content: Thanks. Very clear. There is indeed wrong way info on display that confuses for what current is drawn per rail vs common mid tap. There is a binding post named common in its series output label strip. The PSU owes to be capable measuring for it too when used. Furthermore, not even showing the total voltage since it is supposed to inform for across sections connection only regarding its manual.I hope Siglent can change that via firmware, if it is not rooted to how the series mode relay is wired. Its a flaw not to display the individual currents in regard to the common midpoint. And it can be a showstopper for some thinking to buy those nice, compact, well regulating, and simple to use supplies.

author: tautech
author_rank: Super Contributor
timestamp: June 20, 2015, 08:58:43 pm
content: @ SalasI think I understand now how you probably have arrived at trying to useSeries modefor 2 identical voltage supplies.The display would have confused you to thinking this is possible inSeries modeas when it is selected 2 identical readouts are shown.(did initially for me too)But this is a dual 30V 3A supply and it would be nice to see a front panel option to setup outputs as identical just as some 2 channel AWG's do.However this can be achieved: use a small set of commands with Siglent's Easy Power software as outlined in the manual.http://siglentamerica.com/USA_website_2014/Firmware&Software/Software/Easypower_EN-V100R00B01D01P10.zipIs it still a showstopper?

author: Salas
author_rank: Frequent Contributor
timestamp: June 21, 2015, 02:36:15 am
content: If the custom measurement query config can not be saved so to be available on the PSU screens each time booted, yes its a drag. Can it be saved as reconfigured?

author: tautech
author_rank: Super Contributor
timestamp: June 21, 2015, 08:10:30 am
content: @ SalasI'm still aquainting myself with this PSU, but I think I've found a simple solution.The PSU will store up to 5 setups, and this is very easy to do.Set PSU to desired output settings, pushSave, select setup # and pushSaveagain.To recall the settings just pushRecall, select setup # and pushRecallagain.At next power on, the PSU will start at thelast unsaved settings, then the presetRecallneeds to be activated as explained above.Really very easy.

author: Salas
author_rank: Frequent Contributor
timestamp: June 21, 2015, 09:11:58 pm
content: That sounds promising.

author: Salas
author_rank: Frequent Contributor
timestamp: July 08, 2015, 09:53:43 am
content: Well, I opted for SPD3303S model in the end. Nice small and quiet unit, quality look and feel. Good stability, 1mV 1mA resolution, good accuracy.The query thingmeasure:current ch2?returns what ch1 reads when in series mode. While the voltage readings remain independent between channels.Must be hardwired or firmware locked to only use the ch1 Ameter as reference. A way around it when we must know all of what is going on between the common node and both panel meters for unequal split loads is to use series mode just for tracking when working with the knob, then depress it to go independent again. It takes two (-) black leads to the DUT's power midpoint (or a ch1 red to ch2 blk binding posts link) to stay in series without the help of the internal relay anymore.I would like to propose 1V coarse step too for setting the voltage in such high resolution model firmware if Siglent reads here. Only 0.1V and 0.001V is too much work when not connected to a PC by entering numbers on EasyPower interface.

author: tautech
author_rank: Super Contributor
timestamp: July 08, 2015, 09:58:03 am
content: I'll point Siglent to your suggestions.

author: Salas
author_rank: Frequent Contributor
timestamp: July 08, 2015, 10:05:16 am
content: Hey, thanks. Fine could be assisted by the <--- ---> buttons to just select any next digit for changing.

author: Siglent
author_rank: Regular Contributor
timestamp: July 08, 2015, 10:10:02 am
content: at serial mode, both Channel 1 and channel 2 still have output, so I don't think this display mode is better.

author: Salas
author_rank: Frequent Contributor
timestamp: July 08, 2015, 10:23:54 am
content: Dear Siglent, no need to press ON before fully setting with track and then change to independent.Some Instek models do that also i.e. displaying same current in series mode on both channels ref CH1. Which is clearly wrong when the loading between common node and halves can very well be unequal. Must be addressed. That, and 1V coarse step too, so the Siglent PSU models will be complete for function and measurement. On all other fronts they are very good products indeed, I am happy with mine.

author: rosbuitre
author_rank: Regular Contributor
timestamp: October 09, 2015, 09:21:43 pm
content: HiInstall new version of Easypower P12 for my SDP3303D and the EasyWave P32 and don't work, the previous function OKRegards