FocusMax resolved?

For months, I have been having trouble with FocusMax / ACP interaction problems.

The Problem

FocusMax ( keeps crashing with the typical “Object not set” message. This only occurs when ACP creates a FocuserControl object to adjust the focuser position when a filter gets changed. The crash is intermittent and occurs at different times in the processing. I.e., ACP creates the focuser object, issues perhaps 8-10 commands against it, then releases the object. The crash may occur after any one of the commands.

The ACP AutoFocus.vbs would often fail; the script FilterOffsets.vbs would always fail after 3-5 filters. Typical ACP imaging scripts do regular filter changes for pointing and focusing. These scripts would typically fail after an hour or two. Problems occur with either Maxim5 or Maxim 6, with real cameras or using simulators.

I tried a number of things; eventually I rebuilt the entire observatory computer. I restored the original system from the backup partition, then reloaded all of the software. It continued to fail; now I was also seeing a problem where the Optec was failing to report position to FM.

We (Steve Brady, Bob Denny, myself) were leaning toward some type of hardware issue. So, I went out to map out the USB cables so I could

1) understand how everything was connected,

2) ensure that appropriate USB 1.0 versus 2.0 hubs are being used. I sometimes get a message “This device can run faster” when the STF8300 is powered up.

The map is posted elsewhere. I found a very nice utility USBview, a microsoft tool which unfortunately is not included in the base OS. It draws a useful tree structure showing where evrything is attached and what USB version it uses.

First, I discovered that when I rebuilt the system I installed an old version of the Optec driver (mislabeled folder). Installed the correct version, not the Optec problem is gone.

Second, two weird things happened when I was tracing the USB cables. I was unplugging and re-plugging in cables to make sure I had the right cable/device pairing.

a) twice, when I plugged the cable back into the computer the OS installed the device drivers. Weird, the device was already installed and operating. The system should not need to re-install drivers, they are already there.

b) When I plugged in the Edgeport cable, I got a Blue Screen of Death. The Edgeport supplies 4 RS-232 ports off a single USB cable; I use 2 of these to operate the two focusers Optec and LazyFocus. When the system was rebooted the Edgeport showed up but none of the ports were there. I uninstalled/reinstalled the Edgeport driver, rebooted, and the COM ports were now there.

After weirdness (b), everything is now working. Somehow the USB drivers were “messed up”, but got themselves straightened out. I can now runs AtoFocus.vbs and FilterOffsets.vbs with no problems, using eithere Simulators, the STF8300, or the ST2000M. Everything looks peachy now:)

I moved to FocusMax version 4, the new (non-free) version. Problems continued, with a new wrinkle


Sky Quality Meter

I recently had the opportunity to borrow a Sky Quality Meter from NOAO at Kitt Peak. This allowed me to measure the darkness at my site.

I have tried a couple of ways to estimate the quality. There a couple of techniques where one counts the visible stars in a constellation, and based on the number of visible stars a Bortle reading is made. I came up with perhaps a 5.0-5.2 rating, but it seemed pretty unreliable since I can’t see very well in the first place.

The SQM reads values in units of mag/arcsecond2, so I had to find a conversion from these units to the Bortle scale. I found a web site which did the calculation, so I plotted a variety of SQM values versus the corresponding Bortle values. This turned out to be a line, so I was able to fit the data to a conversion formula:

Conversion from SQM Meter to Bortle readings

Conversion from SQM Meter to Bortle readings

Bortle = 0.6761 (SQM) – 8.0467

My data shows that a) having a partial moon up definitely degrades the value, and b) once I get past about an hour after astronomical sunset, the value stays relatively constant.
Tuesday, Sept 30, 2014      Astronomical twilight ends at 7:30

8:10 PM  19.81, 19.82, 19.80 = 19.81      Bortle = 5.35          1/2 Moon high

10:25PM 20.46, 20.40, 20.50 = 20.45     Bortle = 5.78           Moon low

12:20AM 20.57, 20.66, 20.50 = 20.57     Bortle = 5.86

2:25AM  20.58, 20.61, 20.58 = 20.57     Bortle = 5.87

Wednesday, Sept 31, 2014

7:45 PM 19.11, 18.99, 18.98 = 19.02    Bortle = 4.81           1/2 Moon very high just after astronomical sunset

8:20PM  19.83, 19.62, 19.73 = 19.73    Bortle = 5.29

9:30PM 19.81, 19.89, 19.80 = 19.33     Bortle = 5.02

10:30PM 20.03, 19.99, 19.99 = 20.01  Bortle = 5.48          moon is still high
My sky came out just under 6 (5.87); I am sure that if I had no moon, it would have been over 6. Reassuring, I was worried that the whole move to Casa Grande for somewhat dark sky had been in vain.