Search found 37 matches

by Ben321
Thu Jan 02, 2020 1:07 am
Forum: C and C++
Topic: Why am I losing samples in my application?
Replies: 7
Views: 657

Re: Why am I losing samples in my application?

When streaming the scopes memory acts as a Fifo to help with the flow of data over the USB bus, this data then goes into the driver buffer defined by max_samples, this is a circular buffer and is over written but when you stop streaming either manually or via auto stop it will then have the last ma...
by Ben321
Tue Dec 31, 2019 1:03 pm
Forum: C and C++
Topic: Why am I losing samples in my application?
Replies: 7
Views: 657

Re: Why am I losing samples in my application?

The streaming buffer is a circular buffer defined by the value of max_samples this can be quite large (PC dependent) and is used to buffer data in the driver. The overview buffer is the one used to read data back to the application and the documentation recommends using 15000 to start with and then...
by Ben321
Tue Dec 31, 2019 9:10 am
Forum: C and C++
Topic: Why am I losing samples in my application?
Replies: 7
Views: 657

Re: Why am I losing samples in my application?

It is possibly the fwrite that is causing the problem particularly if you are calling it on each loop, you may need to loop a few times to collect a bigger chunk of data before writing to the file. You may also need to consider the size of the buffer you setup in the driver as this could overflow a...
by Ben321
Mon Dec 30, 2019 7:47 am
Forum: PicoScope 6 for Windows
Topic: I'd like to see a recorder feature.
Replies: 1
Views: 172

I'd like to see a recorder feature.

I'd like a recorder feature in a future version Picoscope, where the sample rate and total number of samples (or alternatively total recording time in seconds) to record, could be specified, and then it records that many samples to a raw file (with or without a WAV file header that includes the samp...
by Ben321
Mon Dec 30, 2019 4:59 am
Forum: C and C++
Topic: Why am I losing samples in my application?
Replies: 7
Views: 657

Why am I losing samples in my application?

I'm writing an application for the Picoscope 2204A. Unfortunately it's dropping samples. Maximum scope sample rate is is 1MHz. And just like the manual says, don't do anything in the callback function other than saving samples, so that's exactly what I'm doing. I'm copying them to an intermediate bu...
by Ben321
Tue Nov 26, 2019 5:50 am
Forum: USB PC Oscilloscopes
Topic: Why is PS2204A resistance so low?
Replies: 1
Views: 267

Why is PS2204A resistance so low?

I did some experiments and calculated that the scope's input resistance is about 1MOhm. That may seem high, but when I'm doing measurements on the output of a circuit, where the voltage I'm measuring is using a 470kOhm pull-up resistor, the scope's own resistance is quite low, and impacts the operat...
by Ben321
Mon Nov 25, 2019 5:59 pm
Forum: Projects
Topic: Proposed new product
Replies: 1
Views: 249

Proposed new product

I'm thinking that with all your 2-4 channel scopes, you are missing out on one possible product. That is a 1-channel scope (aka a high speed digitizer). The purpose for such a device, rather than for comparing 2 or more signals in a circuit, would be to digitize a single signal for analysis on a com...
by Ben321
Wed Aug 07, 2019 10:08 pm
Forum: General Software Discussions
Topic: Why am I getting more values than requested?
Replies: 3
Views: 522

Re: Why am I getting more values than requested?

As you have set AutoStop false, the scope will sample indefinitely, so there is no maximum samples. These parameters are used by the driver to hold a buffer full of raw data that can be accessed after you stop collection. If you only want a set number of samples in total then set AutoStop true. So ...
by Ben321
Wed Aug 07, 2019 7:04 am
Forum: General Software Discussions
Topic: Why am I getting more values than requested?
Replies: 3
Views: 522

Why am I getting more values than requested?

When I use the function ps2000_run_streaming_ns() I'm using it with the following parameters: ps2000_run_streaming_ns(hScope,1000,PS2000_NS,16000,0,1,16000) As you can see, I am running it at 1000ns per sample (that is, a samplerate of 1million smp/sec), and disabled auto_stop (so that later I will ...
by Ben321
Wed Jan 23, 2019 5:03 am
Forum: General Software Discussions
Topic: Question about function ps2000_run_streaming_ns parameters
Replies: 1
Views: 667

Question about function ps2000_run_streaming_ns parameters

What's the difference between the overview_buffer_size and max_samples parameters? In the programmer's guide https://www.picotech.com/download/manuals/picoscope-2000-series-programmers-guide.pdf they are both described as software buffers (which differs from the scope's own internal hardware buffer)...
by Ben321
Thu May 03, 2018 8:51 am
Forum: General Software Discussions
Topic: How to distribute drivers?
Replies: 6
Views: 2529

Re: How to distribute drivers?

For the 2204a, which is a ps2000 unit not a ps2000a, the minimum required dll's are ps2000.dll and picoipp.dll which is used by ps2000.dll You only need ps2000Wrap.dll if your application uses it, it is needed to provide some functionality for certain programming languages that can't work with Call...
by Ben321
Thu May 03, 2018 12:00 am
Forum: General Software Discussions
Topic: How to distribute drivers?
Replies: 6
Views: 2529

Re: How to distribute drivers?

For the drivers you just need to run dpinst.exe which is included in the system folder. This is the Microsoft Driver Package Installer and will put things where they need to be, and register the drivers. The dll's need to be where your application is expecting them, generally with the exe you creat...
by Ben321
Wed May 02, 2018 2:37 am
Forum: General Software Discussions
Topic: How to distribute drivers?
Replies: 6
Views: 2529

Re: How to distribute drivers?

As you have said you will need dll files from C:\Program Files\Pico Technology\SDK\lib, specifically psxxxxx.dll psxxxxxWrap.dll picoipp.dll and the driver files from C:\Program Files\Pico Technology\SDK\sys to match the O/S version of the system you are installing on, not the application. When I c...
by Ben321
Sat Apr 28, 2018 7:00 pm
Forum: General Software Discussions
Topic: How to distribute drivers?
Replies: 6
Views: 2529

How to distribute drivers?

Ok, so if I write a program with the SDK and then distribute my program, I will obviously need to distribute the DLL file for the hardware in question, as it contains functions called by my program. However, the DLL is only an interface to the actual kernel-mode driver that controls the hardware. Th...
by Ben321
Tue Mar 13, 2018 9:57 pm
Forum: USB PC Oscilloscopes
Topic: Antialiasing filter strength?
Replies: 5
Views: 2239

Re: Antialiasing filter strength?

Hi Ben321, You may be placing to much emphasis on aliasing. As explained why, on a previous post, our PicoScopes don't have anti-aliasing filters. So, if you don't want aliasing you need to limit the frequency content of your signal and/or provide a large enough frequency range between the non-atte...