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.