Hello,
recently I have bought Logic MSO Pro 2 Ch and I have a few topics to discuss. Foremost It’s my first time using any MSO previously used only classic bench scopes. Besides a few points marked below I’m very satisfied with new purchase.
How to manually set single shot durations. I want to specify exact recording duration pre- and post-trigger. And also preferably utilize full 1b sample buffer. Currently, I can utilize MAX 524 MS and then sample rate gets reduced by half.
Right now the method of changing window timings is just scrolling in and out the screen. Unfortunately that’s not very convenient because if I zoom in to analyze signal, and then after some time would like to trigger it again then it will record only small portion. To record bigger chunk I’d need to zoom out and trigger again.
Do you plan to prepare some firmware change that allows to use device in Digital Only mode?
Sometimes I will utilize device without Analog part, and this could probably allow device to consume less power (disabling AFE), and maybe it wouldn’t need external power supply.
Also, digital only mode wouldn’t need to stabilize temperature at 50C so active cooling can be reduced.
Active cooling system. From what I see fans are running all the time and that’s fine. However, fans have a rather high pitch fortunately it is pretty quiet, so I can get used to it.
There are not any dust filters at air intake that could be cleaned easily. After longer usage (2 - 3 years of frequent usage) device can get very dusty inside. Is there any approved way of cleaning it?
1 kHz generator, I am being picky right now but my generator generates 988 Hz instead of 1 kHz
@michal Thanks for writing in, and glad to hear you’ve been satisfied with using your MSO so far! Thanks for all the feedback as well!
Single shot durations (Pre-Trigger and Post-Trigger) are currently set via adjusting the horizontal zoom level only. You bring up a great point with regards to recording a fixed single shot length while staying zoomed into your signal!
I’ll mention this feedback to the team here. It would be convenient to set Pre-Trigger length and Post-Trigger length via a fixed numerical value (not affected by zoom).
For setting the buffer lengh, this could also benefit via a fixed numerical value configurable under Single Shot Settings. As a workaround to setting the exact buffer length you’d like, you can specify the horizontal range via numerical input by clicking the bottom-right like in the image below (Setting a 1s range results in a Buffer Length of 1GS in the example image below).
So long as your input signal is within the Max Input Voltage specifications in our Logic MSO datasheet (see below), waveform clipping is safe and you may zoom in and out as you please.
(PS I’m looking into your other questions, but wanted to provide my replies above in the meantime)
On My side there are separate fields (read only) for pre-trigger and post-trigger recording duration.
For ranges up to 500ms it works as you described.
Your buffer length looks wrong for your range and sample rate. How big of a buffer do you have set? It seems like you’re being limited to ~523MB max buffer length somehow (vs. 1GB expected for 1s at 1 GS/s)?
Edit: above was with only one analog channel enabled; if I enable more than one channel, the buffer size required to get maximum resolution goes up. How many (analog and digital) channels do you have enabled? The more enabled, the more buffer size needed to get full range/resolution, otherwise you get the warning:
… so maybe try larger than 8 GB setting to see if it fixes the issue.
(then, decide if you really need full 1 GS/s, or not – reducing sample rate will reduce the buffer size and time required to transfer captured data from Logic to PC memory)
The thing is when the buffer is too small on your side you got notification to extend buffer
On the other hand on my setup PC RAM buffer doesn’t matter. I only get reduced buffer len.
While ago I submitted bug report via form in app. Will see how it goes.
Sorry for the trouble with this - the settings around precise sample rate and buffer length control are a mess right now, and we’re working on improving them. We’re almost done adding direct manual buffer length control that will improve part of this situation, but we still have more work to do after that to really get things dialed in.
That out of the way, there certainly is a bug here that appears to specifically affect the 2 channel, 1 GS/s (100 MHz) 1B sample unit. I have not been able to reproduce it on the 4 channel version with the same properties. Under further investigation, it looks like the software mistakenly computes the maximum buffer length assuming your unit has 4 channels instead of only 2 channels.
We’re investigating right now, but it looks like we should be able to get this fix out as a software update.
We’ll reply once we have an update. Unfortunately I’m leaving on vacation tomorrow, but @huffman is taking this over, and he’s much closer to this part of our application anyway.
I look forward to getting this fixed soon, and again, sorry for the trouble with it!
We are testing a fix now. I will update here once we have it ready for public release. If you’d like a copy earlier, please let me know, I’d be happy to send it over.
