Products > Test Equipment
Siglent - 11/20 - New SDS1104X-U, 4 channel 100MHz, 1Gsa/s economy oscilloscope
nctnico:
--- Quote from: kcbrown on February 03, 2021, 11:07:06 pm ---This means you can use the Instek to see changes to the waveform in rapid succession while still capturing a much larger amount of time when you stop the scope. Obviously, though, the large capture itself only happens when the scope is stopped.
--- End quote ---
No. Try triggering in normal mode on a single event and you'll see there will be a full capture. AFAIK only the newer Keysight scopes have this weird behaviour where you have to stop first (much like pressing the 'single' button) before getting a full acquisition.
kcbrown:
--- Quote from: nctnico on February 03, 2021, 11:09:42 pm ---
--- Quote from: kcbrown on February 03, 2021, 11:07:06 pm ---This means you can use the Instek to see changes to the waveform in rapid succession while still capturing a much larger amount of time when you stop the scope. Obviously, though, the large capture itself only happens when the scope is stopped.
--- End quote ---
No. Try triggering in normal mode on a single event and you'll see there will be a full capture. AFAIK only the newer Keysight scopes have this weird behaviour where you have to stop first (much like pressing the 'single' button) before getting a full acquisition.
--- End quote ---
I should have been more precise. The large capture that contains multiple events that would fire the trigger, where the events are separated by more time than that represented by the distance between the trigger location and the edge of the screen only happens when the scope is stopped. The trigger re-arm time is defined by the time distance between the trigger location on the screen and the edge of the screen, no? If so, then that would mean the trigger can fire any time after the previous event fired plus (at most) the amount of time represented by the screen.
If the trigger re-arm time is defined by the amount of time represented by the capture buffer then that would make the trigger re-arm time independent of the timebase whenever the time represented by the screen is smaller than the time represented by the capture. Is that actually how it works? If so, then I stand corrected, and that would actually reduce the practical difference between the Siglent and the Instek in this regard.
I think I'm going to have to come up with an experiment that shows what the scope does here.
nctnico:
--- Quote from: kcbrown on February 03, 2021, 11:34:35 pm ---
--- Quote from: nctnico on February 03, 2021, 11:09:42 pm ---
--- Quote from: kcbrown on February 03, 2021, 11:07:06 pm ---This means you can use the Instek to see changes to the waveform in rapid succession while still capturing a much larger amount of time when you stop the scope. Obviously, though, the large capture itself only happens when the scope is stopped.
--- End quote ---
No. Try triggering in normal mode on a single event and you'll see there will be a full capture. AFAIK only the newer Keysight scopes have this weird behaviour where you have to stop first (much like pressing the 'single' button) before getting a full acquisition.
--- End quote ---
I should have been more precise. The large capture that contains multiple events that would fire the trigger only happens when the scope is stopped. The trigger re-arm time is defined by the time distance between the trigger location on the screen and the edge of the screen, no?
If the trigger re-arm time is defined by the amount of time represented by the capture buffer then
--- End quote ---
I think you are confusing a couple of things. For clarity:
- trigger re-arm time is the time needed between finishing a capture and making the acquisition hardware ready for the next capture. This is also called dead time.
- the time needed for the acquisition is number of samples * 1/samplerate. So 10Mpts at 1Gs/s takes 10M * 1n= 10ms
The total time for an acquisition cycle is the time needed for the acquisition + the trigger re-arm time + time it takes for an event to appear
What is different between Siglent and other oscilloscopes is that Siglent dynamically alters the number of samples to sample only enough to fill the screen regardless of the memory depth selected by the user.
kcbrown:
--- Quote from: nctnico on February 03, 2021, 11:53:25 pm ---I think you are confusing a couple of things. For clarity:
- trigger re-arm time is the time needed between finishing a capture and making the acquisition hardware ready for the next capture. This is also called dead time.
- the time needed for the acquisition is number of samples * 1/samplerate. So 10Mpts at 1Gs/s takes 10M * 1n= 10ms
The total time for an acquisition cycle is the time needed for the acquisition + the trigger re-arm time + time it takes for an event to appear
What is different between Siglent and other oscilloscopes is that Siglent dynamically alters the number of samples to sample only enough to fill the screen regardless of the memory depth selected by the user.
--- End quote ---
OK, so I apparently did misunderstand how the acquisition of the Instek works. This means the Siglent actually gives you an advantage here, because it gives you fine-grained control over the acquisition rate, whilst the Instek only gives you coarse control by way of specifying the acquisition buffer size.
I'll modify my original message to reflect the consequences of this, because they're not insignificant.
tautech:
--- Quote from: kcbrown on February 04, 2021, 12:07:52 am ---
--- Quote from: nctnico on February 03, 2021, 11:53:25 pm ---I think you are confusing a couple of things. For clarity:
- trigger re-arm time is the time needed between finishing a capture and making the acquisition hardware ready for the next capture. This is also called dead time.
- the time needed for the acquisition is number of samples * 1/samplerate. So 10Mpts at 1Gs/s takes 10M * 1n= 10ms
The total time for an acquisition cycle is the time needed for the acquisition + the trigger re-arm time + time it takes for an event to appear
What is different between Siglent and other oscilloscopes is that Siglent dynamically alters the number of samples to sample only enough to fill the screen regardless of the memory depth selected by the user.
--- End quote ---
OK, so I apparently did misunderstand how the acquisition of the Instek works. This means the Siglent actually gives you an advantage here, because it gives you fine-grained control over the acquisition rate, whilst the Instek only gives you coarse control by way of specifying the acquisition buffer size.
--- End quote ---
Is it not blatantly obvious there are 2 different capture philosophies used by the wfps datasheet spec ?
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version