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Hi,
I know both of these scopes have probably been discussed on here ad nauseum, and the "help me pick an oscilloscope" thing likely gets old quickly, but here I go anyway. Long story short, I'm having a hell of a time deciding between the MSO2072A and the MSO1074Z. It looks like I can get either of them for just under $1000 (USD) via eBay, demo models on TEquipment, etc.
These are some of my considerations:
1. I'm mostly looking to do digital stuff, so I want a mixed signal scope (from what I've gathered the USB logic analyzers suck and I just don't have the space for an old standalone behemoth). Though, according to this document, CMOS and TTL need 400-300ps rise time, so I'm beginning to wonder if my ambition is severely exceeding my budget.
2. As far as I know (and please let me know if I'm wrong about this), both of these models are "hackable": the 2072A to 300MHz and the 1074Z to 100MHz, so the 2072A wins on bandwidth.
3. On the other hand, the 1074Z has four channels, whereas the 2072A has only two. I've only ever had two channels (good old Tek 2230), four would be nice I suppose, but I'm yet too inexperienced to imagine a scenario where I would absolutely need four. Do I want to sacrifice that extra 200MHz (and improvements in some other areas: memory depth, etc.) for another two channels? This is the question that is causing me the most grief.
4. Is there a third option that I'm overlooking or something important that I'm failing to take into consideration?
Anyway, I'd like to hear what people think. -
I don't think USB logic analyzers suck. There are a couple of very nice ones around (e.g. Salae) and all you really want them to do beyond showing the signals, in my limited point of view, is to do protocol decode and that they do very well.
If you need to look at timing issues, like say you have a clock signal running through a couple of drivers or maybe want to create a differential signal using an EXOR and want to look at the skew between the two lines, you'll quickly find out that a 300 MHz scope has insufficient front end bandwidth/timebase resolution to measure the rise time accurately. (interesting Keysight note)
Anyway, I think you should not worry too much about this because a mixed signal scope like the Rigols you mention will do a fine job for most tasks.
Advantage being to show and trigger off either analog/digital channels and display on the same screen, disadvantage that the screen maybe is a bit crowded.
And since you say "digital stuff" I am going ahead and will assume you mean microcontroller/embedded systems - so look at busses, sensors etc. They'll do just fine.
It comes down to how many analog channels you need, and I would like to believe you can do more things with 4 channels most of the time (e.g. SPI) (and don't necessarily need the 16 digital ones). It is also quite a price addition compare to the models without the MSO option.
If I were to offer an opinion on this I would like to believe the DS1000Z-S Plus is better value, but the extra options (arb gen, mso) are going to cost a bit.
I think to recall that the built in generator ( 25 MHz, 14 bit, 16 kPts, 200 MSa/s) is a little less expensive than a comparable standalone Rigol arb gen.
It is very convenient to have those functions inside the scope though, to a point where when you need better functionality you will have to buy much more expensive generators anyway. Only thing I could think of is it a 2-Ch generator would probably be a more versatile choice in the long run.
EDIT, and the third thing you asked, yeah go have a look at what else is out there that could fit your price range from other Manufacturers and also look at the used market. Often older equipment one tier above can be very affordable still. -
I thought the USB logic analyzers were more highly regarded than your choices. I would probably pick the 2000 series but I now may look at another brand, mainstream like I originally expected before getting lulled into the fantasy.
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I don't think USB logic analyzers suck. There are a couple of very nice ones around (e.g. Salae) and all you really want them to do beyond showing the signals, in my limited point of view, is to do protocol decode and that they do very well.
No? I guess maybe I was lumping USB logic analyzers in with USB scopes (which do suck, right?). Anyway, it looks like the 16 channel Salae is $600, plus a 1074Z/Z-S/Z-S Plus puts me a bit over my budget, but may be something I consider.
I really wish there were 4 channel options in the 2000 series since the 1000Z models are only 100MHz, alas the cheapest faster 4 channels are in the 4000 series, which is way out of my price range.
Regarding other brands, I found a Siglent 2074 for $1200 on eBay. That would be pretty much ideal if it had more than 70MHz bandwidth, maybe it's "hackable" a la Rigol? -
The Digilent USB scope seems to get some praise, for what it is.
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uh if you mean that kickstarter one, stay away. It is really not something to use as instrument.
BUT, mentioning Digilent, look at this: http://store.digilentinc.com/digital-discovery-portable-logic-analyzer-and-digital-pattern-generator/
200 USD and pretty powerful. Not really sure how good the measurement pods are in terms of noise etc. but it also doubles up as pattern generator:- 24-channel digital logic analyzer (1.2…3.3V CMOS, up to 800MS/s*)
- 16-channel pattern generator (1.2…3.3V CMOS, 100MS/s)
- 16-channel virtual digital I/O including buttons, switches, and LEDs – perfect for logic training applications
- Two input/output digital trigger signals for linking multiple instruments (1.2…3.3V CMOS)
- A programmable power supply of 1.2…3.3V/100mA. The same voltage supplies the Logic Analyzer input buffers and the Pattern Generator input/output buffers, for keeping the logic level compatibility with the circuit under test.
- Digital Bus Analyzers (SPI, I²C, UART, Parallel)
I can write a little more about this one once I have it here on my desk. Mind the decoding protocol count is a bit limited atm (SPI, I²C, UART) but I could imagine it gets some updates. -
It can not do 5V. What a joke!
uh if you mean that kickstarter one, stay away. It is really not something to use as instrument.
BUT, mentioning Digilent, look at this: http://store.digilentinc.com/digital-discovery-portable-logic-analyzer-and-digital-pattern-generator/
200 USD and pretty powerful. Not really sure how good the measurement pods are in terms of noise etc. but it also doubles up as pattern generator:- 24-channel digital logic analyzer (1.2…3.3V CMOS, up to 800MS/s*)
- 16-channel pattern generator (1.2…3.3V CMOS, 100MS/s)
- 16-channel virtual digital I/O including buttons, switches, and LEDs – perfect for logic training applications
- Two input/output digital trigger signals for linking multiple instruments (1.2…3.3V CMOS)
- A programmable power supply of 1.2…3.3V/100mA. The same voltage supplies the Logic Analyzer input buffers and the Pattern Generator input/output buffers, for keeping the logic level compatibility with the circuit under test.
- Digital Bus Analyzers (SPI, I²C, UART, Parallel)
I can write a little more about this one once I have it here on my desk. Mind the decoding protocol count is a bit limited atm (SPI, I²C, UART) but I could imagine it gets some updates. -
I wouldn't discount all the other capabilities just due to that.
But thanks for pointing out this limitation. Perhaps there is an easy solution (level shifter, passive divider) -
But thanks for pointing out this limitation. Perhaps there is an easy solution (level shifter, passive divider)
Yes there is - reading the specs
: "Setting the voltage to 3.3V, 5V logic inputs are tolerated but the input threshold is 1.42V. LVCMOS 3.3V output signals are compatible to most external logical circuits supplied with 5V."
But yea electrically it's inferior to stuff found in MSOs. -
I have the MSO1074Z-S and I'm happy with it for the money.
On the plus side it's fully featured and takes up little bench space, and because of its size I use it mainly for my field scope, and occasionally in the lab. The LA goes up to 1GSa/s if you only have 8 channels and no analogue channels showing.
On the down side its display is small and it becomes cluttered with many channels showing. Note that using one to eight LA channels leaves you with only three analogue channels, and if you switch on 9 to 16 LA channels you only have two analogue channels available, as resources for the analogue channels are used up by the LA channels.
There are a few little niggles with the firmware and limiting serial decoding to only what's on the screen is the most irritating. Note that the sampling rate drops down to 250MSa/s with 4+0, 3+0, 3+8, 2+8 or 2+16. It's 500MSa/s with 2+0, 1+8 or 0+16.
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But thanks for pointing out this limitation. Perhaps there is an easy solution (level shifter, passive divider)
Yes there is - reading the specs: "Setting the voltage to 3.3V, 5V logic inputs are tolerated but the input threshold is 1.42V. LVCMOS 3.3V output signals are compatible to most external logical circuits supplied with 5V."
But yea electrically it's inferior to stuff found in MSOs.
Sorry but that's not correct -- I also believed that it is so but had been told better: The rigol intergrated arbitrary generators have got a maximum signal span of +-2.5V (5Vss centered around common, into high impedance load). That's actually quite ridiculous and of little use when working with digital stuff powered from 5V. For analog circuitry it may be acceptable though.
Cheers,
Thomas -
So, back at the comp. Reading through the datasheet again:But thanks for pointing out this limitation. Perhaps there is an easy solution (level shifter, passive divider)
Yes there is - reading the specs: "Setting the voltage to 3.3V, 5V logic inputs are tolerated but the input threshold is 1.42V. LVCMOS 3.3V output signals are compatible to most external logical circuits supplied with 5V."
But yea electrically it's inferior to stuff found in MSOs.The supply voltage of the associated FPGA banks is set (by user) to any value from 1.2V to 3.3V.
The threshold level (at the FPGA pins) is about 45% of the bank supply voltage.
For standard voltages of: 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, the threshold levels (at the FPGA pins) are: 0.58V, 0.7V, 0.82V, 1.1V and 1.42V respectively.
Meaning you can set it to anything between 1.2V...3.3V and the threshold will be 45% of that, while for 5V compatibility the threshold will be 1.42V fixed (TTL low is <0.8, high >2V).
I think that is good enough, I don't know how useful values above this are (yeah can easily make a case for it, but most of my circuits are 3.3V or 5V)
keysight's MSO thresholds:User Variable from –8 V to +8 V
And the input voltage range is much better:QuoteMaximum input voltage ± 40 V peak CAT I; transient overvoltage 800 Vpk
The Digilent has 5V2 diode clamping and PTC fuses so it would need external scaling.
Then there is the input impedance which is 100kohm||8pF for the Keysight, opposed to 560k||10pF with 100ohm in the cable tip for the Digilent.
The Digilent however has 2 Gbit of DDR2, which I think I've come to understand is 64M x 24 channels (plus 32k x 16 channels for the pattern generator)
Then the sampling rate, which shrinks the amount of channels for higher sampling rates (only 8 Ch when at 800 MSa/s) while Keysight's does 1.25 GSa/s for 16 channels.
So I think yes the MSO is probably the better and more versatile instrument but they also cost a lot more.
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The rigol intergrated arbitrary generators have got a maximum signal span of +-2.5V (5Vss centered around common, into high impedance load). That's actually quite ridiculous and of little use when working with digital stuff powered from 5V. For analog circuitry it may be acceptable though.
I agree it seems low, but practically speaking I've never found it a hinderance for my work which is mixed signal baseband and RF. For the odd occasion I need to generate arbitrary digital streams I tend to code it on the DUT itself, or use the Analog Discovery. -
Regarding other brands, I found a Siglent 2074 for $1200 on eBay. That would be pretty much ideal if it had more than 70MHz bandwidth, maybe it's "hackable" a la Rigol?
Nobody's done it yet that I'm aware of but the SDS2kX series is on promo at the moment, a SDS2104X with 30% discount is ~ $ 1150. If you buy the MSO SW and HW probe set you get all the other options included, FG and Decode.
I think you can get a further 6% with the members Saelig discount code. -
Regarding other brands, I found a Siglent 2074 for $1200 on eBay. That would be pretty much ideal if it had more than 70MHz bandwidth, maybe it's "hackable" a la Rigol?
This SDS2k without X, they are OLD version (you can see also front panel is different. Poor ergonomy in old model and less memory. X model 2 channel models have 140M and 4 channels models 140M + 140M. (looks like Ebay have lot of these old versions available (perhaps old stock) but also some chinese sources may sell SDS2000 version what are available in China domestic markets.)
It is also good to read factory warranty rules what are valid in different marketing areas.
Current versions are SDS2000X.
And for this SDS2000X serie there is nice Siglent official offer going on at this time.
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If you are looking for a scope with 4 channels, it might be better to wait a little bit more.
Siglent is about to release the SDS1000X-E series based on the Zynq-7000 SoC architecture.
This is only a 2-channels model, and the sampling rate is limited to 1 GS/s.
However, based on previous scope releases, Siglent typically releases the small brother series (SDS1000*) and the bigger brother series (SDS2000*) around the same time.
In other words, this means that they might release the -E edition also for their bigger brother, which would become the SDS2000X-E series. That would be a dream scope: a 4-channel model, with a sampling rate of 2 GS/s, which can do hardware decoding on the full memory (not just on what is visible on the screen). If they also support decoding on the external trigger, that would give you a whopping number of 5 channels for decoding!
Maybe Tautech knows more about this small brother/bigger brother scope release strategy from Siglent!
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It can not do 5V. What a joke!
At the risk of going too off topic, curiousity got the best of me and I found that the Salae pro versions also only support fixed thresholds:Selectable: Vth +0.6V, Vth +0.9V, Vth +01.65V
It does have input protection for inputs up to +/-10V though! -
Pico MSOs: Input dynamic range ±20 V; Digital threshold range ±5 V; Overvoltage protection ±50 V; Two independent threshold controls: Port 0: D0 to D7, Port 1: D8 to D15. Threshold selection TTL, CMOS, ECL, PECL, user-defined. Max sampling rate 500MSa/s with single 8bit group in action*. Saleae Pro keeps 500MSa/s up to 4bit group AFAIK.
*maybe it keeps 500MSa/s with 2x8bit also, dunno, it's not in the spec and I do not have MSO unit.
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Regarding other brands, I found a Siglent 2074 for $1200 on eBay. That would be pretty much ideal if it had more than 70MHz bandwidth, maybe it's "hackable" a la Rigol?
Nobody's done it yet that I'm aware of but the SDS2kX series is on promo at the moment, a SDS2104X with 30% discount is ~ $ 1150. If you buy the MSO SW and HW probe set you get all the other options included, FG and Decode.
I think you can get a further 6% with the members Saelig discount code.
That looks like a viable option. Then again, I can get an MSO1074Z-S for $899 full on retail price. Since this model is effectively 100MHz, after some *cough* "tinkering", and the MSO functionality and probes are included ($488 option on the Siglent), as is the function generator, which is nice, ($188 option on the Siglent), I'm not sure the extra memory (140Mpts vs 24 Mpts), sample rate (2GS/s vs 1GS/s), and capture rate (140,000 wfms/s vs 30,000 wfms/s) are worth it. In fact, with the price of the Siglent, even on sale, plus those options, I could almost buy the MSO1074Z-S and a discounted (i.e. demo, etc.) Rigol 2000 series (which, other than having only 2 channels, is close to the SDS2000X specs if I recall correctly). Of course, this all changes (and I probably buy an SDS2000X immediately) if anybody has been able to hack the SDS2000X series (we're allowed to talk about that here, right?). I think Rigol really has a hole in their lineup where a 4-channel 2000 series should be. -
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Since this model is effectively 100MHz, after some *cough* "tinkering"
I have yet to see a hack path that does not require complicated hardware intervention - but maybe an easy hack exists of which I am unaware. In fact, I am not convinced that anyone has successfully hacked MSO, but am happy to be corrected.Quotethe function generator, which is nice
I find the function generator to be poor, compared to a real AWG.
See Dave's video on MSO versus DS version of Rigol scope.
To me, RIGOL MSO1104Z-S is a great hobby toy, but not suitable as a professional scope.
DS1054Z and separate AWG+LA seems like far better value for money than MSO1074Z-S with poor-mans version of LA and AWG built-in.
But this is just my opinion as an MSO1104Z-S owner. Everyone is entitled to their own opinion
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Since this model is effectively 100MHz, after some *cough* "tinkering"
I have yet to see a hack path that does not require complicated hardware intervention - but maybe an easy hack exists of which I am unaware. In fact, I am not convinced that anyone has successfully hacked MSO, but am happy to be corrected.
I and many others have. It takes a bit of patience, a PC, $20 JTAG emulator and a screwdriver.QuoteQuotethe function generator, which is nice
I find the function generator to be poor, compared to a real AWG.
Maybe, but in what real practical applications are you using a dedicated AWG that you couldn't use that in the Rigol? I'll grant you that the UI is fiddly on the Rigol compared to a dedicated AWG. The only practical scenario I've had is for external modulation, but realistically an AWG is the wrong tool for that job anyway.
But let's see how the Rigol compares to two other scopes' AWG/AFGs I have sitting by me:Code: [Select]Rigol MSO1000Z-S 5Vpp Dual channel, 25MHz Sine, 15MHz Square, AM/FM Modulation (FSK by modulating with square wave)
Keysight MSOX3000A 5Vpp Single channel, 20MHz Sine, 10MHz Square, AM/FM/FSK Modulation
Tek MDO3000 5Vpp Single channel, 50MHz Sine, 25MHz Square, No modulation
So with regards to specs it has a reasonable go at it.Quote
See Dave's video on MSO versus DS version of Rigol scope.
Dave's never had the MSO version of the Rigol 1000Z as far as I know. The vid I think you're referring to talks about the pros and cons of an MSO vs DSO plus USB LA. It's horses for courses, but ever since I've had an MSO (before the Rigol) my assortment of daily driver USB LAs have spent >99% their lives in the desk drawer. Keep in mind there aren't many USB LAs out there with 1GSa/s sampling rate. The bargain basement ones will struggle to deal with even moderate speed SPI buses.Quote
To me, RIGOL MSO1104Z-S is a great hobby toy, but not suitable as a professional scope.
Here's where I strongly disagree. It's a far better scope than exist in many professional workshops I've been in. I'd be interested to know what your criteria are to distinguish the Rigol as a "toy".
These are what I'd call toys in the scope department:
QuoteDS1054Z and separate AWG+LA seems like far better value for money than MSO1074Z-S with poor-mans version of LA and AWG built-in.
It depends on your requirements. For me it's a compact Swiss army knife field scope. If you want to attend site with three different units when one will do, you're welcome to of course!QuoteBut this is just my opinion as an MSO1104Z-S owner. Everyone is entitled to their own opinion
If you really do have this scope as you say, and you think it's so bad, maybe you should take your own advice and sell it so you can purchase a separate Scope, LA and AWG?
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Nice to know that a hack is possible. I clearly have not looked hard enough. Thanks for clarifying the current position.
I respect that others see things differently. I am happy with MSO1104Z, but I knowing spent extra for the extra buttons and connections, for fear of feeling I might be missing out. Better to have the extra bits and not need them than the other way around.
MSO1104Z is fine for me, and I am lucky that value for money was not top priority for me.
Just wanted to make it clear that separate units might be better value for many people. Seems the compactness of an all-in-one solution is good for you (and if I was honest, maybe me too).
As for hobby-verses professional - I used to manage a small repair workshop for a larger company, and I would not have allowed a Rigol in the building, mainly due to the problems of certification of repairs. But I can see that perhaps for self employed professional - or a closely controlled team, that Rigol could be a useful tool, as long as it is used in the right way at the right time.
I am no diplomat, and maybe "toy" was too confrontational a term to use, but the way I use my Rigol (at home) is very much as a toy to me. I started out using scopes similar to the toys that you show, and achieved a lot of success with microprocessor projects using such tools. Rigol certainly is way nicer to use now that I have the luxury of being able to afford such tools, but even the toy scopes (and PICkit2 Logic Analyser) served me well.
As long as potential buyers are aware that built-in LA and AWG have limitations that may, or may not matter, then that was the intent of sharing my experience. No argument was intended.
Seems like the original intention of the OP was to solicit opinions, which was my intention in replying. Apologies if I failed in that endeavour.
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There were some price drops on this series starting on 4/1
www.tequipment.net
Thanks
Evan Cirelli
Vice President and Co-Founder -
There were some price drops on this series starting on 4/1
Good to know. I wonder if this means Rigol is planning some new releases?
I think the MSO1074Z-S is winning right now (-S version because why not?), the specs of the 2000 series are tempting, but I suspect that for my purposes they'll just be bigger numbers that make me feel good about myself, whereas I can actually use the extra two analog channels of the 1000Z series.
I seem to recall some of the Siglents being promising... until I factored in the prices of the options.QuoteAs long as potential buyers are aware that built-in LA and AWG have limitations that may, or may not matter, then that was the intent of sharing my experience.
Regarding standalone logic analyzers, there seems to be a huge gap between the USB "toys" (some of which are apparently OK, though) and high-end standalone units, which are priced way outside of a typical hobbyist budget. Was there ever such a thing as an "entry level" standalone logic analyzer? Have they just been replaced by MSOs? I'd assumed as much, but apparently built-ins have limitations compared to standalone. Older units are dirt cheap on eBay, usually running an old version of Windows and presumably some proprietary software. Picking one of those up is tempting, but they're huge and I find myself wondering what happens when the hard drive inevitably dies and I have to track down Windows 2000 and whatever logic analyzer software, on floppy disks, to get the damn thing working again (has anybody successfully installed Linux on one of these things?).
Strangely enough Rigol has a DS1074Z-S Plus on clearance, but it's listed at $737 which is more than the $699 list price, so I wonder if maybe it comes with the logic probes?