ASI 120mm USB2.0 in Win10

mark4color

I have been using a mono ASI 120mm with SharpCap v.3.1 running in a Win7 environment, connected via USB 2.0 ports. The camera driver version is 3.0.0.4. This configuration has been operating very well.

I recently tried attaching the same camera to a Win10 computer which was equipped with both USB 3.0 and USB 2.0 ports. The camera driver that I downloaded was 3.0.0.7. In both the USB 2.0 and the USB 3.0 ports,, the camera cannot communicate with SharpCap 3.2. The application recognizes that the camera is there, but the application drops almost all frames that the camera sends, regardless of frame rate.

Is there any reason to 'fall back' to an older driver to support this, older, version of the ASI 120 (mono)?

Are there possible changes to the driver settings that could improve performance in Win10?

Should the camera be able to send images to a USB 3.0 port?

Thank you for your advice,

MarkO

katherine.tsai

Does the camera still work well in Win7?

Or it just drop frames in Win10?

Please try this camera in ASICAP, the original ASI software.Check if the problem stills.

mark4color

Katherine.Tsai wrote:

Does the camera still work well in Win7?

Or it just drop frames in Win10?

Please try this camera in ASICAP, the original ASI software.Check if the problem stills.

Hi Katherine,

Yes. the camera still works without any noticeable issues in Win7. Frames only drop when I attach it to may Win10 laptop.

I am attaching a screen capture showing the performance in Windows 7 using ASC Studio, ASICap v.1.0 I also get comparable performance using older versions of ASICAP (1.6.1 and 1.6.2). You can see the frame rates, and relative low rates of dropped frames in the status line at the bottom left. All the tests were done in RAW16 mode.

But, when I attach the camera to Windows 10, the frame rate falls and the dropped frame count rises very dramatically. You can see that data in the lower left of the screen captures that I made with ASI Studio ASICap running in Windows 10. I attach a screen captures -one for MONO8, Things are the same for MONO16. Performance is about as poor with either bit-depth.

For reference, I attach screen snip from my Device Manager for Win7. You will notice a specific controller for USB 2.0. Which does not appear in Win 10 device manager. There I have only Intel(r) USB 3.1 eXtensible Host Controller 1.10 (Microsoft) with USB Root Hub (USB 3.0), and UCM-UCSI ACPI Device. I wonder if this causes problems for USB 2.0. The ASCAP software seems to know that USB 2.0 is being used, but does seem to struggle to read the frames.

Thanks for your assistance. (I hope that you and everyone at ZWO are well and in good health.)

MarkO

W7_USB_Panel.PNGZWO_AISCap_W10_02.pngZWO_ASCIP_03.PNG

katherine.tsai

Sorry to tell you ASI120MM USB2.0 camera is a very old camera and it may encounter some unexpected problem when using with some computers.

wvreeven

The ASI120MM (USB 2) camera doesn't implement the USB2 protocol correctly in the firmware. Basically a packet size of 1024 bytes is used where the USB2 protocol states a maximum of 512 bytes. Many newer operating systems started to enforce the USB2 standard better including Windows 10, Linux (from kernels 4.x up) and MacOS Mojave and Catalina. This is why the frames get dropped.

If you search online then you should be able to find a so called "compatible firmware" that in some cases solves the issue though many people can operate the camera only in 8 bit mode (which is fine for guiding but not for planetary imaging) and many other people never got to make the camera work well at all. I am one of those latter group and I replaced my ASI120MM cameras (I had two) with ASI120MM-S (i.e. USB3) cameras and they have worked flawlessly so far.

HTH, Wouter