Rigol DG800/900 Pro Pulse Capabilities

[NE666]

Hello. I'd like to prevail upon anyone who either owns or has access to any of these to answer a couple of questions on their capabilities and real-world performance.

a) Is it possible to single-shot the pulse waveform? From reading the User Guide, it doesn't appear so. Going by just the description of the front panel controls, the function of the manual trigger button seems limited to starting sweeps/bursts only. Surely it can do something as simple as a one-time pulse?

b) If a single-shot, manually triggered pulse is possible, is it also possible to configure a logic complementary output? i.e. have the output held positive (e.g. +3.5v), with a negative going pulse level (e.g. +0.5v) when triggered?

b) What are the fastest rise and fall times possible for a low frequency continuous pulse output?  Lets say, 0.5Hz at 3.5v pk-pk 0v offset, 50% duty cycle, into 50 ohms.

On paper it seems a reasonably capable general purpose function generator but not, perhaps, the best choice as a pulse generator.

Thanks.

[2N3055]

Hello. I'd like to prevail upon anyone who either owns or has access to any of these to answer a couple of questions on their capabilities and real-world performance.

a) Is it possible to single-shot the pulse waveform? From reading the User Guide, it doesn't appear so. Going by just the description of the front panel controls, the function of the manual trigger button seems limited to starting sweeps/bursts only. Surely it can do something as simple as a one-time pulse?

b) If a single-shot, manually triggered pulse is possible, is it also possible to configure a logic complementary output? i.e. have the output held positive (e.g. +3.5v), with a negative going pulse level (e.g. +0.5v) when triggered?

b) What are the fastest rise and fall times possible for a low frequency continuous pulse output?  Lets say, 0.5Hz at 3.5v pk-pk 0v offset, 50% duty cycle, into 50 ohms.

On paper it seems a reasonably capable general purpose function generator but not, perhaps, the best choice as a pulse generator.

Thanks.

For those requirements Siglent SDG1000X/2000X/6000X can do all of the stuff you asked.

1. You get triggered single pulse by using N Cycle burst mode with number of 1 pulses. Rigol should do that too.
2. Yes. You can invert signal. Rigol should do that too.
3. Setting of rise time is not connected with repetition frequency or pulse width.

SDG2000X is on special right now... It is a 120 MHz, low distortion,  16bit design.

[NE666]

For those requirements Siglent SDG1000X/2000X/6000X can do all of the stuff you asked.

Thank you, that's good to know.

As a matter of personal preference, I'd rather have the form-factor and large touch UI of the Rigol but it needs to deliver on my requirements. And as someone who has already purchased other Rigol TE, I'm starting to see the value of investing in another brand.

[csuhi17]

Hello. I'd like to prevail upon anyone who either owns or has access to any of these to answer a couple of questions on their capabilities and real-world performance.

a) Is it possible to single-shot the pulse waveform? From reading the User Guide, it doesn't appear so. Going by just the description of the front panel controls, the function of the manual trigger button seems limited to starting sweeps/bursts only. Surely it can do something as simple as a one-time pulse?

b) If a single-shot, manually triggered pulse is possible, is it also possible to configure a logic complementary output? i.e. have the output held positive (e.g. +3.5v), with a negative going pulse level (e.g. +0.5v) when triggered?

b) What are the fastest rise and fall times possible for a low frequency continuous pulse output?  Lets say, 0.5Hz at 3.5v pk-pk 0v offset, 50% duty cycle, into 50 ohms.

On paper it seems a reasonably capable general purpose function generator but not, perhaps, the best choice as a pulse generator.

Thanks.

For those requirements Siglent SDG1000X/2000X/6000X can do all of the stuff you asked.

1. You get triggered single pulse by using N Cycle burst mode with number of 1 pulses. Rigol should do that too.
2. Yes. You can invert signal. Rigol should do that too.
3. Setting of rise time is not connected with repetition frequency or pulse width.

SDG2000X is on special right now... It is a 120 MHz, low distortion,  16bit design.

I'm not 100% sure, but I couldn't find a solution.

1. Rigol doesn't know, the Pulse waveform doesn't work in "Sweep and Burst" mode. The device also informs you about this: "Sorry unable to burst Pulse waveform"
You can do it with a square wave, but it also includes the negative part.
If you set an offset, it is continuously active by activating the channel.

When I tested it, I didn't check that the "Idle Level" was set to the center.
changed to 1st Pt, top or bottom is good.
Thanks to zrq for pointing it out.

2. can invert a signal and can set an offset

3. Pulse in continuous mode 0.5Hz, 3.5Vpp 0 offset and 50%.
3ns for rise and fall.
the frequency doesn't affect it

but the pulse width is affected by the frequency.
At 1 Hz, 100us or 0.01%
100ns at 1kHz, which is also 0.01%
9ns at 1MHz, 0.09%

You cannot have a 1Hz pulse with a width of 9ns.

Unfortunately, there is no easy way to use your own wave yet, it is not possible to know for sure if burst or sweep would work with it.

[Njk]

1. Rigol doesn't know, the Pulse waveform doesn't work in "Sweep and Burst" mode. The device also informs you about this: "Sorry unable to burst Pulse waveform"

The Pro can't burst Pulse?

[csuhi17]

no can't no burst no sweep
DG 912 Pro

[TurboTom]

Really? Then, what's pro with the "Pro" series? Even my DG811"+" can do this (N(=1) cycles mode Pulse, manual or external trigger). The "idle" level can be configured so it's very well possible to generate a no-brainer, manually triggered pulse. The second channel could be used to generate a complementary pulse if necessary. I didn't test if the generator will trigger both channels simultaneously from the manual trigger button, but there's no reason why it wouldn't. Since both channels have individual aux inputs, just feeding the same trigger signal to both would also enable to generate a complementary, triggered, single pulse...

The more I read about the shortcomings of the recently released "800/900" series of instument, the more I wonder what Rigol had in mind when they didn't do their homework and afterwards apparently don't try to correct things with very frequent firmware updates. It's a shame that most of their older gear performs better and offers more features than their most recent releases, even if this older stuff is far from bug-free. I really hope they get their things together and improve on that!

[2N3055]

.........
The more I read about the shortcomings of the recently released "800/900" series of instument, the more I wonder what Rigol had in mind when they didn't do their homework and afterwards apparently don't try to correct things with very frequent firmware updates. It's a shame that most of their older gear performs better and offers more features than their most recent releases, even if this older stuff is far from bug-free. I really hope they get their things together and improve on that!

Thomas,
those are exactly my sentiments. It feels like Rigol fires whole design team and burns old design documentation and every new generation is a clean slate design based on requirements compiled as some "feature list" that was formed by solely marketing department.
It almost feels like they are outsourcing actual instrument development and that core team is disbanded after every instrument generation is put into production...
It sounds crazy, and I know they should have large engineering team, but ....

I guess that is what having no long term operational strategy looks like...

[zrq]

(a): You can do that with the square wave. You can set burst with single cycle and the level when idle can be arbitrary set, not sure about the problem described by csuhi17.
(b): Can not find a way to do that with manual trigger, I can put both channel in manually triggered mode, but the trigger button will only work for the currently selected channel.
However it's easy to do when using the external trigger.
(c): Certainly <1.75 ns for a DG821pro hacked to the full 200 MHz, measured with a hacked >500 MHz DHO1074 as a upper bound. But there is a firmware bug causing the output can be scrambled when generating continuous slow (<1Hz) square waves like you described.

Given DG8xx pro and 9xx pro are based on a quite new platform, I would expect they will have a relatively long service life and firmware support life. Unfortunately, currently the firmware is in a usable but far from perfect state.

[Njk]

They provide a hardware solutions

[2N3055]

(a): You can do that with the square wave. You can set burst with single cycle and the level when idle can be arbitrary set, not sure about the problem described by csuhi17.
(b): Can not find a way to do that with manual trigger, I can put both channel in manually triggered mode, but the trigger button will only work for the currently selected channel.
However it's easy to do when using the external trigger.
(c): Certainly <1.75 ns for a DG821pro hacked to the full 200 MHz, measured with a hacked >500 MHz DHO1074 as a upper bound. But there is a firmware bug causing the output can be scrambled when generating continuous slow (<1Hz) square waves like you described.

Given DG8xx pro and 9xx pro are based on a quite new platform, I would expect they will have a relatively long service life and firmware support life. Unfortunately, currently the firmware is in a usable but far from perfect state.

If you read OP question he needs to be able to control rise/fall times. You cannot do that with squarewave, hence pulse signal.
So no that AWG cannot. Sad part is that old DG1062Z can.

[TurboTom]

They provide a hardware solutions

Then they should open source it...

[2N3055]

They provide a hardware solutions

It doesn't work that way..

I bought a device that is, say, AWG. It is a device that provides function. FW and HW is one monolithic thing to me.
If there is no signal on output, I don't care if it is broken relay, or bug in code that simply don't switch on relay because of low quality of code.

If manufacturer provides quick and timely software fix, that is fine for small annoyances.
If they don't give good software and all the time something is wrong....
It does not work, i send crap back.

[zrq]

True, and it seems the only way to get a controlled rise&fall time is to program an ARB. Hope burst of pulses is something that will be added to the half baked firmware.

BTW the fall time tested is even slightly faster of <1.7 ns . This is probably superior to SDG2000X though which specified to be <8ns iirc (only using one at work, no chance to test it).

[2N3055]

True, and it seems the only way to get a controlled rise&fall time is to program an ARB. Hope burst of pulses is something that will be added to the half baked firmware.

BTW the fall time tested is even slightly faster of <1.7 ns . This is probably superior to SDG2000X though which specified to be <8ns iirc (only using one at work, no chance to test it).

If by superior you mean faster, than it is faster.. SDG2000X has cca 7-8 ns rise/fall times.

But if you don't need edges faster than 8 ns but good control than SDG2000S is vastly superiors to Rigol. Eye of the beholder and actual needs in practice rule...

[tautech]

True, and it seems the only way to get a controlled rise&fall time is to program an ARB. Hope burst of pulses is something that will be added to the half baked firmware.

BTW the fall time tested is even slightly faster of <1.7 ns . This is probably superior to SDG2000X though which specified to be <8ns iirc (only using one at work, no chance to test it).

If by superior you mean faster, than it is faster.. SDG2000X has cca 7-8 ns rise/fall times.

But if you don't need edges faster than 8 ns but good control than SDG2000S is vastly superiors to Rigol. Eye of the beholder and actual needs in practice rule...

SDS1000X ~1/2 that.

[NE666]

Thank you to everyone who has chipped in here, some very valuable information which has certainly prevented a "misfire" (Rigol have a sale on at the moment and I was getting ready to pull the trigger).

My particular thanks to both csuhi17 and zrq for taking the time to verify actual behaviour on hardware.

I really would prefer to not have the Siglent as I don't enjoy that 'recycled HP' form-factor / aesthetic anywhere near so much as I used to before other options hit the market.  I also think the UI shows it age (but don't we all, in the end?). However one cannot deny that the purpose of TE is to serve specific requirements and to serve reliably, so Siglent it (probably) is. I no longer have sufficient confidence in Rigol's software development that a FW fix will ever be forthcoming, let alone within a timescale that fits mine.

 

[2N3055]

Thank you to everyone who has chipped in here, some very valuable information which has certainly prevented a "misfire" (Rigol have a sale on at the moment and I was getting ready to pull the trigger).

My particular thanks to both csuhi17 and zrq for taking the time to verify actual behaviour on hardware.

I really would prefer to not have the Siglent as I don't enjoy that 'recycled HP' form-factor / aesthetic anywhere near so much as I used to before other options hit the market.  I also think the UI shows it age (but don't we all, in the end?). However one cannot deny that the purpose of TE is to serve specific requirements and to serve reliably, so Siglent it (probably) is. I no longer have sufficient confidence in Rigol's software development that a FW fix will ever be forthcoming, let alone within a timescale that fits mine.

I own (and use) DP831A, DG1062Z and DM3068 from Rigol. I used to own a DS1074Z too.

I had them all before "going over to Siglent side"....
Which I did because last two generation of equipment from Rigol was huge disappointment to me..

While I could plainly see Siglent is steadily improving, in a visible, tangible, way..

[Njk]

Perhaps this is the result of different business strategies. Siglent used to work for the other brands as well so it can enjoy a better access to help, consultations and advices from them, while Rigol insists on its own brand (probably for better access to government funding) so no one can educate them on the art of decision making

[Njk]

If by superior you mean faster, than it is faster.. SDG2000X has cca 7-8 ns rise/fall times.

BTW the times can depend on the output amplitude. Is that number for whole amplitude range or only for small amplitude values?

[2N3055]

Perhaps this is the result of different business strategies. Siglent used to work for the other brands as well so it can enjoy a better access to help, consultations and advices from them, while Rigol insists on its own brand (probably for better access to government funding) so no one can educate them on the art of decision making

I don't know about Rigol. But Siglent seems to be more professional exactly because they insist on quality of their brand. I don't think it others "patronizing" them, but quite the opposite direction. They want to learn and make quality products.
They remind me of "old HP" a bit.
Rigol seems to be less concerned about building quality brand. They seem to think they already are and there is no need to get better. They are approaching things like they make consumer products.
That is how it seems to me.

[2N3055]

If by superior you mean faster, than it is faster.. SDG2000X has cca 7-8 ns rise/fall times.

BTW the times can depend on the output amplitude. Is that number for whole amplitude range or only for small amplitude values?

As far as I know (from datasheet) that is guaranteed at 1 Vp-p /50 Ω... that is 2 V amplitude.
I don't know until what amplitude  they hold that, I don't have 1000x/2000x here, I can only check on 6000X...
I don't think 7000A is relevant here...

[NE666]

True, and it seems the only way to get a controlled rise&fall time is to program an ARB. Hope burst of pulses is something that will be added to the half baked firmware.

BTW the fall time tested is even slightly faster of <1.7 ns . This is probably superior to SDG2000X though which specified to be <8ns iirc (only using one at work, no chance to test it).

If by superior you mean faster, than it is faster.. SDG2000X has cca 7-8 ns rise/fall times.

But if you don't need edges faster than 8 ns but good control than SDG2000S is vastly superiors to Rigol. Eye of the beholder and actual needs in practice rule...

SDS1000X ~1/2 that.

That's not what the datasheet says. "<12ns (10% ~ 90%)"  for square waves and "7ns Rise/Fall time (10% ~ 90%,typical,1 kHz,1Vpp)" for pulse.

I stand corrected by myself, I'd been reading the SDG1000 (vs SDG1000X) specs. The SDS1000X isn't half, it's actually double (according to the specs): "Min. 16.8ns Rise/Fall" for pulse.  Which is one of the reasons that I'd hoped the 800 Pro would work out.

[Njk]

Anyway for my Rigol DG800 the min. pulse rise/fall time setting is 8 ns for the amplitudes of up to 6V PP (into 50 ohm) and 20 ns for greater amplitudes. I think something similar can be the case with the other gens like this because the output amplifier capability depends on the amplitude.

[2N3055]

Anyway for my Rigol DG800 the min. pulse rise/fall time setting is 8 ns for the amplitudes of up to 6V PP (into 50 ohm) and 20 ns for greater amplitudes. I think something similar can be the case with the other gens like this because the output amplifier capability depends on the amplitude.

You are absolutely right. Output amplifiers will have slew rate limit..
These are NOT dedicated pulse generators, they are general purpose AWG that actually treat pulse same as any other signal, going through output amplifier. What you get is great versatility, not absolutely uncompromised cutting edge pulse performance.

But, for many uses they are good enough, or even great if slew rates and amplitudes numbers good enough for you, and they give you great options.
One thing I use a lot is WaveCombine, where you can mix bot channels right there on the AWG, easily creating aggressor signals, or some complex combinations.