A review of the GWInstek 1054B

[maxwell3e10]

It came with version 1.18

[saturation]

That's essentially the best and latest, and the one I currently use too. v1.19 the only difference in the changelog is supported languages.

It came with version 1.18

[anilnediyara]

First of all let me thank Saturation for this long thread on 1054B.  I am looking at this scope and GDS1102B for use mainly in audio amp service and 3phase VFD.

My question is which one will be better for each application. The faster FFT analysis of this scope looks impressive for checking the harmonics of VFD's.

[saturation]

You're welcome.  I think this thread exists by accident as there is no one else discuss the 1000B series.

IMHO issues that may affect your choices:

1000B is suited as a bench instrument and has no protection for power electronics use.   Its natively a CAT 1 device.  While it can help troubleshoot 3 phase VFD but you will need isolating the front end with a HV differential probe, which can cost as much as this low cost DSO depending on the frequency and rated voltage

The chassis is easily transported, but may not survive one drop to floor from 3'

FFT has ~ 50dB noise floor due to 8 bit resolution

FFT pick up spurs generated by the DSO, e.g. its SMPS or the internal clock, they are a constant so you can figure out which spurs are artifacts, spur amplitude can varies as you set the FFT

My 1054B is not rated by an electrical safety organization such as UL, ETL or CSA

IIRC, the DSO in the 1000B series are identical make except for the -3dB frequency response and available channels.  However you can see the lowly 1054B can gives useful response to ~80MHz with 4 channels on.

Any 1000B can help audio applications, but audio specifically the "50MHz" 4 CH version is more than adequate

First of all let me thank Saturation for this long thread on 1054B.  I am looking at this scope and GDS1102B for use mainly in audio amp service and 3phase VFD.

My question is which one will be better for each application. The faster FFT analysis of this scope looks impressive for checking the harmonics of VFD's.

[saturation]

I can recreate your issue and will post a photo later, so concur with your result, I think you have found an anomaly or if it was on purpose, an economizing measure.  It would be interesting to see if the same artifacts occur on the 2000 series  using the Zynq platform.

I have always wondered if the gaps were wfms/sec related but they are independent of the memory depth or the sampling rate, so its occurring during data acquisition phase.

Here is a more proper test using a linear ramp. One can see gaps in the data, which are also in the saved waveform. I believe the reason is that in the firmware they do some vertical scaling while keeping only 8 bit numbers.

Another problem I found is that on high sensitivity scales it does not have true 8-bit resolution. For example, on 1 mV scale, all bit values are spaced by 3. So they simply rescale the values instead of increasing the analog gain.

In terms of responsiveness, I found the horizontal shift knob has rather large lag.

[akimmet]

I can also recreate this issue on my GDS1102B.

I can't complain too much since I have gone 2 years occasionally noticing those gaps in dot mode, and not thinking much of it.

[saturation]

@maxwell3e10:  I'd be interested in your thoughts on what you think this anomaly does to affect the accuracy of the DSO or performance.  I do not know what practical significance it has after the re-tests I ran.  Screen caps to follow.

Here are my thoughts:

It does not affect the published spec sheet vertical accuracy of ~3% across all its ranges and frequencies, both visually measured as well as using automated values

The 'anomaly' does not contribute more distortion or artifacts than the 8-bit CPU can resolve, [ beyond the gaps shown ] and performing FFT on the test waveforms do not show extraneously spurs above the noise floor of ~50dB.

If the ADC were effectively sampling using less bits, the noise floor would rise.

Its unclear if this is from the HMCAD1511 ADC, Zynq SoC or Instek's firmware.

Finally, there is no practical lag in the response to the controls, but if you have some objective measure I can retest it for you.  Suffice to say, you move a knob the screen responds instantly.  The lag however is worse as you turn on more channels, increase the memory depth and turn on the math.  However you can control the response by simply turning off what you don't need at the moment, the fastest speed up is reducing the memory depth, then turning them back on or increasing the memory depth in sequence to get best resolution, or use the "STOP" mode and examine the issue after data has been acquired.  The good news with this design is the speed vs resolution tradeoff is under user control.

[maxwell3e10]

I noticed it right away because I haven't seen such gaps in other scopes. I don't entirely understand the effect. It looks as if they do some vertical scaling of the ADC values. But the scaling depends on how many channels are being sampled, it makes no sense. It does have effectively fewer bits, but only about 25% fewer, so the increase in noise is not significant.

I got the scope specifically for an application where I want to display 10M points per channel and all 4 channels. So perhaps its not surprising that it is a little slow.

[maxwell3e10]

I got a confirmation from Instek that this is in fact part of the design:
"It’s because the dynamic range of A/D converter can’t 100% match the front end attenuation circuit .
 Thus we use digital amplifier"

[saturation]

Thanks, good and new info which I think no one has tried to figure out.  So kudos to you.  And that makes sense as an 'economy' move.  That GWInstek was able to squeeze this type of performance from the low cost platform is, IMHO, another plus.

I recall the Hittite ADC has a built in "digital zoom" function that the spec sheet claims would not marked affect the SINAD and I presume the 'accuracy', but naturally ENOB is reduced because it simply scales to the amplitude without resampling.  They say ENOB of > 7.5 from 8 bits, which sounds like what might happen given what you found, but your data seems the ENOB is far less than 7.5 bits.

Relevant items from the data sheet:

http://www.analog.com/media/en/technical-documentation/data-sheets/hmcad1511.pdf

8-bit High Speed Single/ Dual/ Quad ADC
 Single Channel Mode: FSmax = 1000 MSPS
Dual Channel Mode: FSmax = 500 MSPS
Quad Channel Mode: FSmax = 250 MSPS
• 1X to 50X Digital Gain
 No Missing Codes up to 32X
• 1X Gain: 49.8 dB SNR. 10X Gain: 48 dB SNR
• Internal Low Jitter Programmable Clock Divider
..
• Coarse and Fine Gain Control
• Digital Fine Gain Adjustment for each AD

...

. Internal 1 to 50X digital coarse gain with ENOB > 7.5 up to 16X gain, allows digital implementation of
oscilloscope gain settings. Internal digital fine gain can be set separately for each ADC to calibrate for gain errors.

I got a confirmation from Instek that this is in fact part of the design:
"It’s because the dynamic range of A/D converter can’t 100% match the front end attenuation circuit .
 Thus we use digital amplifier"

[maxwell3e10]

Regarding the digital gain it says in the HMCAD1511 datasheet: "There will be no missing codes for gain settings lower than 32x (30dB), due to higher than 8 bit resolution internally". This is actually surprising, that the ADC has intrinsically 13 bits!
But it seems that Instek is using it less than optimally. Instead of using this internal gain feature they must just multiply the output by a factor and end up with missing codes.

[saturation]

It frankly doesn't matter, as the final output is limited by 8 bits or less as specified in the data sheet regardless of their internal bit length. 

As for whether the Instek code is at fault for producing the anomaly, you cannot say whether the effect is from Zynq SoC, the use of ADC internal gain or Instek's firmware code, or a bit of all. 

Regardless, since the DSO does what the GWInstek data sheet says it should do regardless of the gaps you examined, what you have found is an academic exercise, but no practical significance.

Regarding the digital gain it says in the HMCAD1511 datasheet: "There will be no missing codes for gain settings lower than 32x (30dB), due to higher than 8 bit resolution internally". This is actually surprising, that the ADC has intrinsically 13 bits!
But it seems that Instek is using it less than optimally. Instead of using this internal gain feature they must just multiply the output by a factor and end up with missing codes.

[maxwell3e10]

You really like to defend it! Anyway, even apart from these gaps, I am not that impressed. The input noise is rather high and on 1 mV/div setting the vertical resolution is very poor, less than 100 bits. I would say the only thing this scope has going for it is 4 vertical control knobs, one per channel, which is rare.

[nctnico]

The 1mV/div range is zoomed indeed. Then again if you want to do sensitive measurements then you might want to use a (differential) amplifier anyway.

[rauldm]

The Math channel can work with filter app? for example I put a equation in math channel like (atan(ch1/ch2)), Can get output of  this function filtered with filter app?

[nctnico]

The Math channel can work with filter app? for example I put a equation in math channel like (atan(ch1/ch2)), Can get output of  this function filtered with filter app?

Yes and no. The filtering comes before the math operation.

[rauldm]

The Math channel can work with filter app? for example I put a equation in math channel like (atan(ch1/ch2)), Can get output of  this function filtered with filter app?

Yes and no. The filtering comes before the math operation.

Thanks for your answer, I would have liked to buy this oscilloscope  for atan function and filter, I think only Pico scopes has this function, perhaps R&S too, but for good price like this scope would be excellent buy option,  in user manual math mode and filter function it comes bad explained, you don't can know more for example how filter can work with math channel.

[WI_Hedgehog]

I cannot find a way to set the Date/Time. I checked everything under the Utility menu without success. The scope readings recorded to USB drive therefore have a timestamp of 12/31/1979_11:00PM, which isn't exactly great from a recordkeeping standpoint.

[tautech]

I cannot find a way to set the Date/Time. I checked everything under the Utility menu without success. The scope readings recorded to USB drive therefore have a timestamp of 12/31/1979_11:00PM, which isn't exactly great from a recordkeeping standpoint.

Barely any 1000 series scopes of any brand offer a RTC.

[mwb1100]

The GDS-1000B Series User Manual  has this to say about setting the date/time:

System Settings and Miscellaneous Settings

This section describes how to set the interface, language, time/date,
probe compensation signal, erase the internal memory and access
useful QR codes.

But as far as I can tell it never actually documents how to do it (though it does explain in detail how to bring up some QR codes to get you to the GDS-1000B website).  Are you sure you've looked at all the various sub-menus of the Utility menu?  I don't have a GDS-1054B, so I'm no help beyond what the manual says - or doesn't say.

[nctnico]

Pressing the utility button on the scope brings up the configuration menu and in that menu, setting the time/date should be one of the choices IF the GDS-1000B series has an RTC. The bigger brother (GDS-2000E series) has an RTC but the manual for the GDS-1000B series shows an empty spot in the menu where the GDS-2000E series has the time/date menu button. So my conclusion would be that the GDS-1000B series doesn't have an RTC and thus you can't set the time/date on it.

[mwb1100]

I don't see why a lack of an RTC would mean that there wouldn't be a reason to allow someone to set the date/time. Way back when, personal computers didn't have RTCs - you had to set the date/time whenever the computer booted.  I can understand why people often wouldn't be bothered to do that on Oscilloscopes, but they should still have the option for reason that WI_Hedgehog gave: people would want files and screen captures to have the correct date/time (does the 1054B display the date on screen?).  But I suppose whether or not to provide the small feature is GW-Instek's decision.

The SDS1104X-E doesn't have an RTC (though it does support NTP if you a network connection), but it lets you set the date/time.

One similarity between the GDS-1054B and SDS1104X-E is that the user guides for both mention that there's a data/time setting function in the Utility menus, but neither actually documents how.

[tautech]

The SDS1104X-E doesn't have an RTC (though it does support NTP if you a network connection), but it lets you set the date/time.

This was a recently added feature to support the then also new Logging feature to provide the required timestamps for logging.
A NTP connection can be set to Sync at boot to your local NTP server via a WiFi or LAN connection and give accurate file timestamps and display real time on the display if you wish. I've even done it via a hotspot from my phone.

AFAIK it's one of the few 1 GSa/s DSO's that can do this.

[WI_Hedgehog]

I read the manual several times (i even have it printed in color and bound), searched online, looked under every related menu item... no time setting that i could find. It doesn't have WiFi but does have Ethernet, though I don't have internet where the scope is used (nor an NPT Server). I even read the 2000 Series manual hoping there was a trick i was missing...I guess a GW adding a RTC costs another $5 if all related costs are considered, so they skipped it.

Thanks for the answers/help, with everything it does I thought an RTC would be standard equipment.

[Hydrawerk]

There are 2 marked changes compared to 1.09 not described elsewhere on the Internet, as of this post.  There is a noticeable increase in overall speed compared to 1.09, but not quantifiable.

• A trigger out in now available from the probe compensation port, just turn the adjust knob until option appears
  
  

Is this documented in the user manual in 2023? Is the trigger out available even at other GW Instek scopes like GDS-2000E, MSO-2000E or MDO-2000A?