ASI294MM-Pro problem with PemPro

Muggsie

I have been working with PemPro support since early March on a problem that occurs when my ASI294MM takes an image in that program. Error messages occur and the image is not saved. We have tried numerous tests, but they do not have a solution. The ZWO ascom driver is up to date on my computer (3/18/2021). The problem also occurred with the previous ZWO ascom driver. The camera is working fine for me otherwise. Here is the link to the thread with screen shots of the error messages. I'm running Windows 10 Pro and nothing else is running on the computer other than PemPro V3. I have also removed and re-installed PemPro with no change in the problem.

https://ccdware.infopop.cc/topic/error-saving-image-in-calibration-wizard?reply=668140555265248968#668140555265248968

Please take a look and see if you have a solution. Any help would be appreciated.
I would like to use PemPro V3 to measure my mount's PE with my 294MM.
Thanks - Mark Tenboer

Tech@ZWO

I think you may contact the author of PemPro for this issue.

Muggsie

I contacted the author of PemPro Ray Gralak and he acquired an ASI294MM and recreated the problem. Here is his message back to me.

raygralak PEMPro Authority
"I got my ASI294MM and I was able to reproduce the problem. It seems the ZWO ASCOM driver allocates almost 600MB of memory when an application just connects to it, then goes over the 1GB limit for a VB.Net application and fails. I created a very simple Visual Studio project with about 120 lines of code and I got the ZWO ASCOM camera driver to fail. The ZWO ASCOM Camera driver should not require 1GB of memory for a single 40+ megapixel image. Maybe you can share this video with ZWO. I can provide the VB.Net project for them to try if they can't reproduce the problem.
One more data point here. I used the ASCOM Camera Simulator driver instead of the ZWO Camera ASCOM driver with the same simple application I created for my previously posted video. To create an unbinned 48MPixel image required at least 600 Megabytes less memory than the ZWO ASCOM Camera driver.
See this YouTube he made on this problem.
https://youtu.be/pqPpRv_sh0Y

I'm not a techie, so it would be most efficient if ZWO could communicate directly with Ray at this link to the thread at PemPro support. I am hoping you can reduce the memory usage for the ASCOM driver so it does not crash other astrophotography programs.

https://ccdware.infopop.cc/topic/error-saving-image-in-calibration-wizard?reply=669125949975916520#669125949975916520

Thanks - Mark

Tech@ZWO

Muggsie
We do not allocate and limit memory in ASCOM, and other upper level software such as MDL, NINA, SGP through ASCOM do not have this problem, there is nothing need to be done from our side.

SiriusImaging

Hi, I just tried using MaximDL Pro 6 with my ASI294MM using the latest ZWO ASCOM driver (NOT the native ZWO driver), and I am getting this error:

Has the ASI294 passed ASCOM Conformance testing with your latest ASCOM driver? If so, could you post the conformance test results here?

Thanks,

Ray (author of PEMPro)

Tech@ZWO

SiriusImaging
"-1" is illegal for offset.

SiriusImaging

Good day @tech@zwo#44935

We do not allocate and limit memory in ASCOM,

There is no method to allocate memory in ASCOM, but memory can be allocated in an application (including an ASCOM driver) automatically in many ways. For instance, when the ASCOM driver specifies an array, memory can be allocated.

For the ASI294MM, the ZWO ASCOM driver uses over 950 Megabytes of RAM in the process of producing a single unbinned image. Doesn't that seem like an unreasonably large amount of memory for a single 40 megapixel image?

And I have proven that this is not a PEMPro issue because even a simple 122-line 32-bit VB.Net application exceeds memory limits. Here's a link to that Youtube video again:

https://youtu.be/pqPpRv_sh0Y

Something in the ZWO driver's code is creating a memory buffer that is excessively large. All I ask is that someone familiar with the ZWO driver ASCOM driver development try to check the amount of memory being used when taking an image. As a point of reference, I found that the ASCOM platform's Camera Simulator (ASCOM driver) uses about 600 megabytes less memory for a similar-sized image using the same 122-line simple program in the video.

-Ray

Tech@ZWO

SiriusImaging
We need buffer for pre process, and you can refer to NINA(open source) which has no problem through ASCOM.

SiriusImaging

Good day @tech@zwo#44962,

We need buffer for pre process, and you can refer to NINA(open source) which has no problem through ASCOM.

I can easily make my 122-line program work by compiling it as a 64-bit application, to accept the 1GB of memory that your ASCOM driver needs for a single image. Unfortunately, it is not possible to switch PEMPro to 64-bit because it uses 32-bit DLLs to talk to some legacy hardware so it cannot run as a 64-bit application.

NINA uses WPF, but PEMPro was created over 18 years ago using Windows Forms, which is a predecessor to WPF. WPF has less memory limitations than Windows Forms. To change an application from WinForms to WPF would require a complete rewrite.

I noticed that the memory does not jump until the ASCOM client asks for the data. If the ZWO ASCOM driver needs memory for preprocessing, it could be disposed, or freed, before the final image is transmitted. Note that the exception in the code is happening within the ZWO ASCOM driver, not the 122-line application. It is unfortunate that your developers cannot find a way to use memory more efficiently in the ZWO ASCOM driver.

-Ray

Tech@ZWO

SiriusImaging
Thanks for your opinion. We will find a way to optimize this.

SiriusImaging

Good day @tech@zwo#44985,

Thanks for your opinion. We will find a way to optimize this.

Thank you!

-Ray