Products > Test Equipment

Pocket-Sized 6 GHz 1 TS/s ET Scope

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SJL-Instruments:
Sorry for not making that clear. Flashing the FPGA should resolve the issue.

Future updates can be done over USB in the software, and will only require selecting one .dfu file.

joeqsmith:
No problem.  The latest manual does talk about the FPGA rev 14,  but having programmed it a few times I didn't read it.  Anyway, it is now programmed and working fine.   I'll give it a trial run tomorrow after I get some sleep and provide you with an update. 

Thanks

joeqsmith:
What is the key sequence you select to reset the Maximum Triggers/Sample to infinite?   

Have you considered adding tool tips (help) when hovering the mouse over a control?   

Power user mode, why when I select a start of 11n, the actual start is 10.997n?    12 is 11.998.  End at 18 gives 18.003.   

When selecting the auto setup, often the CDF range will be set such that the signal isn't smooth.   It provides a good starting point (see attached ch1,  Setting to even 50m will clean this up)

To oversimplify, I use a scope to see how the amplitude of a signal varies with time.  Any scope I have used, allows me to set a time base and input gain to get what I want.  With your scope, the user is now introduced to statistics.  Something users may have no interest in.   I mention this after having a conversation with a friend after they had spent some time reading this thread.  The jist of the conversation was, what is all this math stuff...   Because of the focus being more on the statistics and not actual use, I think they perceive it to be more an interesting science project than a lab tool.    It would be interesting to hear from others. 

SJL-Instruments:

--- Quote from: joeqsmith on March 22, 2024, 08:28:40 pm ---What is the key sequence you select to reset the Maximum Triggers/Sample to infinite?   

--- End quote ---
You can enter "inf" or "infinity" to reset the setting to infinity.


--- Quote from: joeqsmith on March 22, 2024, 08:28:40 pm ---Have you considered adding tool tips (help) when hovering the mouse over a control?

--- End quote ---
We have not considered this yet, but certainly can add them. We have added this to our to-do list.


--- Quote from: joeqsmith on March 22, 2024, 08:28:40 pm ---Power user mode, why when I select a start of 11n, the actual start is 10.997n?    12 is 11.998.  End at 18 gives 18.003.   

--- End quote ---
This is so that the timebase lines up correctly in intensity/color-grading mode. This is more clear with few points in the timebase.

As an extreme example, consider having only two points in the timebase at 10ns and 11ns. Then the intensity-grading at 10 ns would fill the region from 9.5 to 10.5 ns, and the intensity grading at 11 ns would fill the region from 10.5 to 11.5 ns. If the endpoints were labeled as 10 ns and 11 ns, the timebase and cursors would not line up correctly.


--- Quote from: joeqsmith on March 22, 2024, 08:28:40 pm ---When selecting the auto setup, often the CDF range will be set such that the signal isn't smooth.   It provides a good starting point (see attached ch1,  Setting to even 50m will clean this up)

--- End quote ---
Thanks for catching this - will be fixed in next update.


--- Quote from: joeqsmith on March 22, 2024, 08:28:40 pm ---To oversimplify, I use a scope to see how the amplitude of a signal varies with time.  Any scope I have used, allows me to set a time base and input gain to get what I want.  With your scope, the user is now introduced to statistics.  Something users may have no interest in.   I mention this after having a conversation with a friend after they had spent some time reading this thread.  The jist of the conversation was, what is all this math stuff...   Because of the focus being more on the statistics and not actual use, I think they perceive it to be more an interesting science project than a lab tool.    It would be interesting to hear from others. 

--- End quote ---
This goes back to the origins of the scope. At first, we did not intend to target eye diagrams or SI applications.

If looking only at single-valued signals, there is no need to mess with any of the CDF settings. For applications such as measuring the risetime of clocks, or the relative timing of pulses, the scope "just works" and is a quite useful practical tool. Our first few customers fell under this use case, and found the scope very easy to get started with.

Later we realized that the scope is technically capable of intensity-grading and eye diagrams, but this requires understanding of the statistical theory of operation. We implemented these features so that the hardware was not limited by the software, but we do recognize there is a learning curve. Again, had we known this during development, we would have made different choices.

The products we currently have under development will "just work" for their intended application. Certainly we have lost many potential customers for SI applications due to the perception you mentioned. From our perspective, the best thing we can do is to learn from this experience, and apply it to our future products.

joeqsmith:
Thinking about the FPGA, have you considered adding a revision register that would be exposed to both the firmware and  software?  Rather than the crash and burn when there is an incompatibility problem, you could report the issue.   With the new method of programming, are you suggesting users will never run into the possibility that the firmware and FPGA are not compatible?


--- Quote from: SJL-Instruments on March 22, 2024, 08:58:39 pm ---
--- Quote from: joeqsmith on March 22, 2024, 08:28:40 pm ---Power user mode, why when I select a start of 11n, the actual start is 10.997n?    12 is 11.998.  End at 18 gives 18.003.   

--- End quote ---
This is so that the timebase lines up correctly in intensity/color-grading mode. This is more clear with few points in the timebase.

As an extreme example, consider having only two points in the timebase at 10ns and 11ns. Then the intensity-grading at 10 ns would fill the region from 9.5 to 10.5 ns, and the intensity grading at 11 ns would fill the region from 10.5 to 11.5 ns. If the endpoints were labeled as 10 ns and 11 ns, the timebase and cursors would not line up correctly.

--- End quote ---
Sorry but I don't understand.  Using your example, I would sample at 10n & 11n.  I would end up with a set of PDF data at each time.  I would just plot the intensity of these two data sets.  At least that is how my software currently works. 

I repeated my random data test, allowing it to run several hours.  I noticed that it appeared the scope had stopped responding to all messages.   So I shutdown my software and started yours.  It does not find the scope.   Windows sees the communications port.  Using my software, I am able to establish a connection to the port but the scope does not respond to any commands.   

I had asked about how to program the device with custom software and wonder if these new commands could have locked up the unit.  Still, if that was possible, I would have expected your software would be able to clear it.  Power cycling the scope did return it to normal operation.   

I also tried to collect data using the new firmware/FPGA with my software.  It appears that something has been changed that broke my code.  So, I tried the original software that you provided (v2.5.3) and it also no longer is able to run the scope.  Guessing you are aware of this and the new manual documents these changes.   

***
v2.5.12 also does not work with the latest firmware/FPGA.   This version is new enough, I would expect it to notify the user with some sort of error about the firmware being too new.  Instead, it just doesn't collect any data.

***
Looking at the new manual, there isn't a section about what was changed to the protocol.   I was expecting something big enough to break the software would have been in a "whats new" in the Programming Guide.   I guess I need to diff the two versions of manual to find out what was changed.   

***
Comparing the two PDF manuals Programming Guide section, I see the following changes:

Note: Revision 14 of the firmware will perform this monotonicity correction automatically.

Internally, the delay will be measured and fine-tuned to achieve an accuracy of 0.2 ps or better.
This process takes ∼8 ms. If the optional argument y is set to 1, the verification will be skipped,
saving time in exchange for a typical accuracy of ∼2 ps.
Note: The parameter y is ignored in firmware revisions v13 and earlier.

• [Firmware v14 and later] The optional parameter y determines the CDF return format. If y
is set to 2, then the returned CDF values have 16-bit precision. Otherwise, 8-bit precision
is used.   

Note there is no mention of the Y parameter in the latest manual's example code.  This may be the problem, but I would expect it to default to what ever the old firmware did as to not break your own software.   Odd also is the manual makes no further mention of the 8-bit precision in this section and assumes everything is integer based.   Seems like a last second feature (fast mode?) and wasn't well thought out?


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