AC2020bsi not initializing consistently in MaxIm DL 6 or 7

Freshly rebooted Win11 computer, freshly started DL7 (7.0.3, DLAPI 2.8.0.0), camera connected via USB. Powerup camera, wait 5 sec after fans start, press Connect in Camera Control, Setup Tab. Wait a few seconds after fan speed goes to high, go to Expose Tab.

At this point, usually Readout Mode shows what I always use (High Gain), and taking an image will occur normally and FITS header will have a READOUTM entry. But when I Disconnect, power down, wait 10 sec, and repeat the above, sometimes Readout Mode on the Expose Tab will be blank and the dropdown arrow does not bring up the usual menu of readout mode options. Pressing Expose at this point will result in a normal-looking exposure, but its FITS header will NOT contain a READOUTM entry. I have not delved in to the internals of the FITS file to see what the sample values are. See attached screen capture.

Sometimes, instead of showing a blank Readout Mode box, the box comes up showing HDR mode, even though that is not what I last used. In such a case, the dropdown arrow functions properly and I can choose the readout mode I want (High Gain). The image then appears to be acquired normally.

It MIGHT be the case that waiting longer before moving to the Expose tab prevents this (blank or HDR Readout Mode), but obviously there is a problem here.

I also get this running Win7, DL6 (6.4.0, DLAPI 2.8.0.0). And in one instance (just 2 days ago) this coincided with the “bad histogram” problem I’ve had with my camera (and that was SINCE my camera’s latest trip in for repair of that problem). In this case 2 days ago, the computer was not freshly rebooted before the test run, and DL6 had not been freshly restarted (since starting DL6, I had done an overnight observing run, using an ST8 and its driver) so the test was not as “clean” as what I just described with the Win11/DL7 test.
I have not yet seen the bad histogram problem running the recently returned camera with DL7, but testing continues.

I will attach the following:

- a screen capture showing the Expose tab with blank Readout Mode box, the image that was just taken, and its FITS header
- the image taken with Readout Mode blank (image10.fit)
- the previous image (image9.fit) taken where all had been normal Readout Mode "High Gain"


Gary Billings