DATE-OBS errors from MaxIm DL

[William Bristow]

Hi Grady.

That was a reported bug, introduced in MaxIm DL v6.21, where random .fits header values were recorded in the DATE-OBS key.

Fixed in MaxIm DL v6.22 but then there were a few more changes to the DATE-OBS key in subsequent MaxIm DL versions that also required bug fixes.

Specifically for MaxIm DL v6.21 it was suggested that a work-around for the DATE-OBS error is to open Camera Control, Settings, and for both Camera 1 and Camera 2 enable the Advanced options at the bottom of the U.I. window to access the camera and filter wheel using separate process threads, at the time MaxIm DL v6.21 was released both those options were disabled by default and enabling them seemed to fix the DATE-OBS bug, later releases of MaxIm had those options enabled by default.

In connection with ACP there may be random errors with controling the camera when those advanced threading options are enabled, some internal race condition in the software, which is very much linked to the PC hardware that ACP and MaxIm run on and therefore very unpredictable with only a few users experiencing problems.

Now that the release notes for MaxIm DL 6 have been withdrawn from the Diffraction Limited web pages you would need to search the MaxIm DL user forum using DATE-OBS as a search term to discover when the changes and bugs affecting the DATE-OBS key in the .fits header for MaxIm DL v6.xx were finally fixed, from memory I think it was around version v6.26, I would need to find a working copy of MaxIm DL v6.50 to read the release notes in full from the built-in help document.

Maybe I can dig out an archived copy of MaxIm DL v6.50 and install it on a VM later today (UK-GMT time) and see which release of DL 6 had the last mention of fixes for DATE-OBS but the release notes don’t always include everything, sometimes they’re just listed under “Various fixes and improvements”, you’ll most likely get more accurate information if you ask on the Diffraction Limited MaxIm DL forum which was the last release of MaxIm DL 6 that had all known bugs in the DATE-OBS .fits header field fixed.

In the interim, check those Advanced threading options in MaxIm’s Camera Control U.I. and if disabled try enabling them for both camera and filter wheel, both cameras, and see if that fixes the problem but if you find that sporadic errors and “hangs” of ACP and MaxIm occur with those advanced threading options enabled then the only solution is to upgrade MaxIm DL 6 to at least v6.26 (I think).

So, not a problem that QHY need be concerned with AFAIK.

HTH

William.