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Picoscope demo mode triggers extremely slowly?

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Picoscope demo mode triggers extremely slowly?

Postby jeremy » Sun Mar 23, 2014 7:00 am

Hi,

I'm looking at buying a 3400 series picoscope and I have been playing with the demo software under Win8 VMWare in Mac OSX. Unfortunately, the triggering in the software is slow as molasses even with simple edge triggering. If I turn triggering off (set to none), I get a display update rate of probably 10-20Hz (which is totally fine!). However, if I turn on any of the triggers I get at *best* 1Hz and at kHz frequencies single/repeat trigger simply does not work.

I only do the following things:

1. Open the software, and click yes to the demo device prompt
2. Change the triggering dropdown in the bottom right to "Single"
3. Change the threshold to 0.5V
4. wait a few minutes for a trigger

Or alternatively:

1. Open the software, and click yes to the demo device prompt
2. Change the triggering dropdown in the bottom right to "Auto"
3. Change the threshold to 0.5V
4. triggers at <1Hz on a 1kHz sine wave

The software still says "running" in the bottom right, but no waveforms ever get displayed. Am I doing something wrong here?
jeremy
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Re: Picoscope demo mode triggers extremely slowly?

Postby alan » Sun Mar 23, 2014 9:57 am

Hi,


The PicoScope 3400 and all our scopes with deep memory have built in hardware acceleration which ensures screen update rates much faster than any other USB scopes and also much faster than most benchtop scopes. At fast timebases you get 1000s of updates per second. Even when collecting huge amounts of data per waveform (>100 million samples per waveform) the scope will still update many times per second. In this respect it is much faster than benchtop scopes costing orders of magnitude more.

When you run in demo mode the software has to emulate the hardware acceleration so things are a bit slower, but even then your results seem odd. Try the following

A) Click on the home icon at the top (loads default settings)
B) Set the trigger to auto
C) Click on the autosetup icon to the left of the home icon.

For me that gets a fast update rate even in the demo software with no hardware attached.

If you set the trigger to single as you mention below it should trigger once then stop
If you have the trigger set to repeat it will trigger once per trigger even (check the trigger diamond is within the waveform - if its above / below or you have enabled an advanced trigger such as pulse width it may not trigger).
If you set to auto it will trigger every time it gets a trigger, but if there is no trigger it will update the screen once per second.

Give the above a try and let me know how you get on.
alan
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Re: Picoscope demo mode triggers extremely slowly?

Postby jeremy » Sun Mar 23, 2014 10:54 am

Hi again Alan,

I received your private message, but unfortunately the forum will not allow me to send or reply to private messages so I am replying here. In answer to your questions, I am using OSX Mavericks 10.9.2 with all of the latest software updates on a 1 month old Macbook Pro Retina 13". Other versions that may be useful:

Windows 8.1 with all updates installed, VM allocated 6GB of physical RAM
VMware Fusion 6.0.2 which is the latest version
Picoscope 6.8.10.13

The system and UI is perfectly responsive even when picoscope is behaving slowly.
jeremy
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Re: Picoscope demo mode triggers extremely slowly?

Postby Martyn » Sun Mar 23, 2014 1:55 pm

I will check this through when in the office tomorrow, but it just looks like the demo device is not triggering correctly, or at all, hence the one second update when in auto and no trace when in repeat mode.
Martyn
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Re: Picoscope demo mode triggers extremely slowly?

Postby Martyn » Mon Mar 24, 2014 3:51 pm

I haven't been able to test this out on a Mac yet, but all appears to be OK on a variety of Windows systems unless the trigger is not met by the signal. Can you try

File->StartupSettings->ResetStartupSettings

File->StartupSettings->LoadStartupSettings

to put the software back to default, and then set Trigger from "None" to "Auto" and see if the trigger works correctly, and the diamond sits on the trace.
Martyn
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