AnsweredAssumed Answered

Why are Agilent scopes not able to measure in the sample memory?

Question asked by 0xdeadbeef on Jun 1, 2012
Latest reply on Apr 20, 2014 by JohnMiles
Don't get me wrong, I just ordered a DSOX3024 for our department (honestly as there was not enough money for a better option) and it is indeed a very neat little scope for the price that I like much more than the more expensive MSO7000A someone bought some years ago. Indeed a lot of things that I hated about the 7000A were improved. Yet it still shows a few quirks of the older models:

1) It measures in the display memory. So automatic measurements are usually inaccurate until you zoom in long enough. There is no indication whatsoever for the user to know when a measurement is inaccurate or not. You just have to try.
I really wonder who designed this and why. With a scope that as up to 4GS/s sample rate, you would expect that you can easily measure in the nanosecond range or (slightly) below. Instead automatic measurements are never more accurate than 10ns and depending on the display resolution, you can easily end up in the microsecond range even though the sampling rate is > 1GS/s. 

2) There is no gating implemented. Ok, you can zoom in and do the (auto) measurement in the zoom window, but this is not gating as you can't move the left and right side of the gating area independently. Now really, every other bigger brand supports proper gating - why doesn't Agilent?

3) There is no dedicated key for switching between auto and normal trigger mode. Agreed, at least the DSOX3000 let's you define the quick action key to switch between these trigger modes, but why the heck doesn't Agilent finally put a dedicated "Auto/Normal" key next to the Run/Stop and Single buttons?

I really wonder if Agilent scope developers simply don't care about these issues or if there is some kind of ideology behind it. For #1 I could imagine that this is a limitation based on the signal path needed to create the high waveform update rate. But not everybody thinks that you need a million waveforms per second and sacrificing measurement accuracy for pseudo-analog behavior is a pretty bad idea for a lot of applications. Also be aware that e.g. LeCroy salesmen are well aware of these limitations and use them to sell their scopes.  

Outcomes