DS1074Z 4 Channel or DS2072 2 Channel Oscilloscope?

[Williamscullen818]

Hello, I've been looking into purchasing an oscilloscope recently and thought I had decided on the new Rigol DS1074Z but now I'm questioning my reason.
I like the bigger screen, 14 horizontal divisions, dedicated knobs per channel, waveform record knob, and everything else about the DS2072 except the fact that it is only 2 channels.
For the most part I'm working with digital electronics, serial decoding, and general purpose analog circuits. I wanted the ability to display all the required signals for SPI on the scope at once
for debugging, which is why i was leaning towards the DS1074Z originally. Also, I've seen the insides of both scopes now and it seems like you get more scope for your dollar with the DS2072.
2072 has the AD Black Fin DSP in it vs. the Freescale version in the 1074. Seems to me like I'll be getting more of a scope for my money with the DS2072

My questions is to those of you who are like me and do mostly digital debugging of circuits, and general purpose analog (nothing high bandwidth). Do you find it important and useful to have a
4 channel scope over a 2 channel scope? Is it worth missing out on the goodies of the DS2072 for a 4 channel DS1074Z to be able to view all 4 channels of an SPI bus at once? Anything below $1000 for me is doable, I'm not worried about the extra $250 it would cost me to get the DS2072. If I got the DS2072 I would need to switch between MOSI and MISO or not show the CLK/CS when viewing a signal. I would love to get a DS4014, but that guy it out of my price range. Obviously the hack available is a big factor in this as well, tequipment.net no longer sells the DS2072, only the newer version DS2072A. I'm not sure of the differences but I've heard that hack is not yet available for the newer A version yet..? I'd like to hear your input? Anyone with one of these scopes care to share their experiences with them? I heard someone say on another thread that if you need 4 channels you could always buy another DS2072 down the road, but I'm not convinced that is a reasonable option...

Thanks,

[echen1024]

Search is your friend, my friend

[EEVblog]

My questions is to those of you who are like me and do mostly digital debugging of circuits, and general purpose analog (nothing high bandwidth). Do you find it important and useful to have a
4 channel scope over a 2 channel scope?

Not really. You can do that with a cheap USB logic analyser. It you need to check serial line signal integrity then you can do that one line at a time usually.
Bottom line is I wouldn't make my scope choice based on analog input for digital serial decoding if that's your only reason.
YMMV

[nctnico]

I would never consider buying a scope with less than 4 channels. There are often more than 2 signals which have interesting information.

[nowlan]

I think you will find a lot of people recommend a dedicated logic analyzer for troubleshooting serial protocols.
Saleae Logic

[linux-works]

I'm also looking for a nice 4ch scope (not urgent but if the right one comes along at the right price).

I have a 16ch logic analyser (seed studio thing) but I'd still prefer to not use my pc if I don't have to, and instead use the thing with real knobs and a dedicated os/cpu for the task.

it could be useful to see the shape and noise levels of the lines you are monitoring, even if digital.  rise time and even voltage levels are important and a pure logic sniffer won't show that.

so, if I care about the bits only, sniffer it is.  if I have to see why things 'mostly work but sometimes dont', then I prefer an analog style display, even if its from a digital scope.

I was thinking strongly about the tek 2465b, but its 2nd pair of channels don't have a proper atten knob (they only have a 2 pos switch, which is 'ok' for logic but not nearly good enough for true 4 chan mixed mode operation).

if you are going for a scope, I do suggest trying for 4ch.

[BravoV]

I was thinking strongly about the tek 2465b, but its 2nd pair of channels don't have a proper atten knob (they only have a 2 pos switch, which is 'ok' for logic but not nearly good enough for true 4 chan mixed mode operation).

Own 2465B, channel 3 and 4 of 2465B are basically crippled compared to 1 & 2, I believe they're intended mostly for digital signaling work only.

[electronics man]

I just got the ds1074z and I love it the 4 Channels is great.

For the extra $250 you could get the z-s which has a function generator so you get a basic logic analyse and with the 4 chan and and a function generator. I personally think that the ds1074z is the best value for money you won't go wrong its am excellent scope go for that one

[Williamscullen818]

Ok, seems like most of you feel that 4 channels is important to have. Now, I could also get a open logic sniffer from dangerous prototypes along with the ds2072 to satisfy my needs for more 2 channel digital work, they are about $50 depending on where you buy it.

Can anyone convince me to purchase the DS1074Z over the DS2072A/logic sniffer for digital work when the price point has no significance?

[electronics man]

you coukd get the ds1074z and a much better logic analyser for more + ds074z doesnt have some of the problems as the ds2000 series as it is newer. i feel that you should futureproof yourself whith the 4 channels as you may be stuck in a situation where you need 4 channels such as looking at a sine wave propagating through a circuite although you say you do digital now in a few years you may be interested in analog. 

[linux-works]

just get 2 scopes

based on all the talk, here, a year or two ago, I got the tek 2225 low noise analog scope.  its great for audio and times when I need to see the actual look of the waveform.  no fan, either, so that's nice.

then, due to more talk here, I got the famous 2ch rigol that can be hacked to 100mhz.  nice small unit and good price.  but if I were deciding now, I would pass on that one and go directly for the 4ch version and still keep the tek analog.

when I can justify the money for the 4ch version, I'll probably put my rigol 2ch up for sale.  can't see the point of having two rigol scopes.

think about a used tek analog scope in addition to your 4ch digital one.  as for funct gens, I prefer to have that in its own box, so I can change it or upgrade it as I need.

[echen1024]

I will admit that the DS2072 plus logic sniffer is a more attractive choice over the DS1074Z. Why? First, you are getting a better scope. More memory, more refresh, higher bandwidth, etc. 2, your logic capabilities will be better. Rigol does all software decoding, and that makes it slow as hell. While the same is done on a USB logic sniffer, computers are much faster. Also, you get the capability to monitor multiple serial buses at once, and maybe even 1 parallel in the case of 8 channels, or more for 16.

[Electro Fan]

Ok, seems like most of you feel that 4 channels is important to have. Now, I could also get a open logic sniffer from dangerous prototypes along with the ds2072 to satisfy my needs for more 2 channel digital work, they are about $50 depending on where you buy it.

Can anyone convince me to purchase the DS1074Z over the DS2072A/logic sniffer for digital work when the price point has no significance?

I went through some of the same decision-making you are going through.  I had a chance to try both the DS1104Z and the DS2072.  To me the biggest trade-off was between 4 channels (on the 1000) and the functionality of the Nav knob (on the 2000).  In the end I went with the DS2072.  I'd like the extra 2 channels but I decided the ability to examine captured signals more easily with the Nav knob and related features was more important than the extra 2 channels.  I think many users here would prefer the 4 channels - so it's definitely not a universal opinion.  On the other hand lots of users here have a DS2000 - so it just comes down to your specific needs and preferences.  I think for SPI having the extra 2 channels would be beneficial but if you are willing/inclined to also purchase a logic analyzer then I think the 2072 will give you a slightly better ability to examine signals than the 1000Z and you can still look at digital signals with the logic analyzer.  Ideally we could all afford a MSO with 4 analog channels and 16 digital channels so we could look at plenty of signals and easily correlate them in time but at some point it gets pricey unless you have a pretty compelling need, cost-justification, or healthy budget. 

You can't go far wrong either way; the 1000Z is an excellent scope and offers a great value for the price and likewise with the 2000.  Let us know what you decide.  EF

[Williamscullen818]

Can the DS2072A decode both MOSI and/or MISO without the clock signal on the display, or does the scope require the clock signal for decoding? Maybe this is the wrong place to ask, but does anyone know if a memory dump is required to hack the DS2072A, or does the riglol website keygen work for both DS2072 and DS2072A? Because the DS2072 is no longer available through tequipment.net, only the newer DS2072A.
http://www.tequipment.net/RigolDS2072.html

[Pasky]

There was a neat video showing the serial decoding on a high end Rigol scope vs an Agilent and Tektronix, and the Rigol was missing data every now and then.  I'd get the DS2072, and buy a logic analyzer.

[Williamscullen818]

Was it this video?

[Pasky]

Yup. That's the one.

[Mark_O]

Can the DS2072A decode both MOSI and/or MISO without the clock signal on the display,

No.

...or does the scope require the clock signal for decoding?

Yes.  One channel must be CLK.  The other can be MOSI _or_ MISO.  So only one direction can be seen at a time.  There's been some discussion on how it would be nice if Rigol made better use of the ExtTrig input, and enabled CLK there.  Thus making the full-duplex SPI traffic visible.  But that's been owners talking, not Rigol. 

Also, there's no channel for CS, or Device Select, so if you actually have multiple devices on the multiple device SPI bus, you won't be able to select which one to monitor.  Only the DS1000Z or DS4000 series provide full SPI support.

Maybe this is the wrong place to ask, but does anyone know if a memory dump is required to hack the DS2072A, or does the riglol website keygen work for both DS2072 and DS2072A?

Yes, this is the wrong place to ask.

[Mark_O]

There was a neat video showing the serial decoding on a high end Rigol scope vs an Agilent and Tektronix, and the Rigol was missing data every now and then.  I'd get the DS2072, and buy a logic analyzer.

When I saw that video, I was  shocked.     Shocked I tell you!  Who could have imagined that scopes costing "only" >$5,000-6,000 USD more than the MSO4024 would actually perform better, in some ways?  That was really damning for the Rigol.   

I'm curious how many engineers, when debugging serial bus comms traffic, find it effective to monitor the decoded data stream in real-time?  Especially when you can't go back and check something that looked interesting?  Personally, I find it rather difficult to grok constantly flashing and disappearing byte strings.  Even when it's relatively slow (very unusual!) as in the demo setup.  I normally like to set up and capture a sequence of traffic, especially when I have a device with a deep memory capacity.  Then go back and step/slide through the exchanges, go backwards if needed, etc.  In that mode, the Rigol (like most software-driven decoders) wouldn't have the same difficulty keeping up as shown in the live demo.

Lastly, given the $10k+ price tag on the Tek scope demo'ed, I wasn't all that impressed with the display.  Yes, it seemed like the decoded info was being updated, but neither the clock trace nor the data trace seemed to be updating properly, as both the Agilent and Rigol were.  (The Rigol trace updates seemed about half as fast as the Agilent, but at least they were changing in a visible way.  The Tek just seemed to flicker occasionally, and you couldn't even tell there were two different length bursts.)

[Mark_O]

There was a neat video showing the serial decoding on a high end Rigol scope vs an Agilent and Tektronix, and the Rigol was missing data every now and then.  I'd get the DS2072, and buy a logic analyzer.

Which logic analyzer would you recommend, that would display decoded serial bus traffic in real-time, as the ~$10,000 Agilent was? 

[echen1024]

Try a used Agilent 16700 series, such as the 16702B, or a Tektronix TLA type analyzer.

[Electro Fan]

There was a neat video showing the serial decoding on a high end Rigol scope vs an Agilent and Tektronix, and the Rigol was missing data every now and then.  I'd get the DS2072, and buy a logic analyzer.

I normally like to set up and capture a sequence of traffic, especially when I have a device with a deep memory capacity.  Then go back and step/slide through the exchanges, go backwards if needed, etc.

If I understand this correctly it is the reason that tipped me from the Rigol DS1000Z to the Rigol DS2000.  The ability to fairly quickly and easily navigate during the review process (with the big Nav knob and related features/buttons/controls on the DS2000) is IMO a pretty valuable advantage of the DS2000 vs. the DS1000Z.  (This is not intended to start a big battle about the value of 4 channels - all other things being the same, 4 channels is better than 2 channels, especially if you need 4 channels).

No doubt the Rigol DS4000 is a great choice as it brings 4 channels and the Nav functionality.  And no doubt it would be nice to have the speed of hardware rather than software enabled performance (as offered by Agilent)- so there are some great choices beyond both the DS1000Z and the DS2000 if you have the budget. 

If the next version of the DS1000Z was a MSO1000Z with 4 analog channels, 8-16 digital channels, and the big Nav knob functionality... now that would be cool.

[Pasky]

There was a neat video showing the serial decoding on a high end Rigol scope vs an Agilent and Tektronix, and the Rigol was missing data every now and then.  I'd get the DS2072, and buy a logic analyzer.

When I saw that video, I was  shocked.     Shocked I tell you!  Who could have imagined that scopes costing "only" >$5,000-6,000 USD more than the MSO4024 would actually perform better, in some ways?  That was really damning for the Rigol.   

I'm curious how many engineers, when debugging serial bus comms traffic, find it effective to monitor the decoded data stream in real-time?  Especially when you can't go back and check something that looked interesting?  Personally, I find it rather difficult to grok constantly flashing and disappearing byte strings.  Even when it's relatively slow (very unusual!) as in the demo setup.  I normally like to set up and capture a sequence of traffic, especially when I have a device with a deep memory capacity.  Then go back and step/slide through the exchanges, go backwards if needed, etc.  In that mode, the Rigol (like most software-driven decoders) wouldn't have the same difficulty keeping up as shown in the live demo.

Lastly, given the $10k+ price tag on the Tek scope demo'ed, I wasn't all that impressed with the display.  Yes, it seemed like the decoded info was being updated, but neither the clock trace nor the data trace seemed to be updating properly, as both the Agilent and Rigol were.  (The Rigol trace updates seemed about half as fast as the Agilent, but at least they were changing in a visible way.  The Tek just seemed to flicker occasionally, and you couldn't even tell there were two different length bursts.)

I don't understand your point other than you want to be condescending towards me.  Regardless of the price of those scopes, you're talking about a $4000 Rigol scope that's isn't recording (at least I think it wasn't recording, maybe it just wasn't displaying it all but still captured it?   I'm unsure, it doesn't really explain it, but that's what I assume, If I'm wrong, then well, I'm wrong) all the serial data coming from an Arduino, yes, an Arduino......  It's well known that the Rigol's use software for signal decoding that video is an excellent example of how slow it really is.  If you're considering purchasing an even lower model, expect THAT kind of performance or worse from it was my point, it's better to just get a dedicated logic analyzer if that's the case.

[RRobot]

If I had to diagnose a I2C communication issue, and I spent an afternoon trying to diagnose why bytes were missing on the I2C bus. Then later found out that they were not missing but that the scope simply lost them ( and I2C none the less), I would throw that scope right out of a window.

[linux-works]

if the scope really could not keep up with 'simple' i2c, yes, I agree, it would be frustrating beyond belief.

you need to trust your tools.  digital capture (unless you agree you are ok with simple 'sampling') should be lossless and reliable.  if its not, its less than useless.