Adjusting autofocus parameters for PFE on 8530F

[Dan R]

Hi John-
Autofocus through PFE *sometimes* works for our 8530F -- the JEOL autofocus appears to work a little better -- it looks like it is scanning over a larger range in z. What parameters should i tweak in the ini file to try to adjust the autfocus parameters for the 8530F?

[John Donovan]

Hi John-
Autofocus through PFE *sometimes* works for our 8530F -- the JEOL autofocus appears to work a little better -- it looks like it is scanning over a larger range in z. What parameters should i tweak in the ini file to try to adjust the autfocus parameters for the 8530F?

Hi Dan,
Unlike the 8900/8200/8500 auto-focus call (which is a Z stage scan using the optical signal with many adjustable parameters), for the 8x30 instruments we have to call the EIKS API function that JEOL provided.  Unfortunately they do not indicate that there are any adjustable parameters for the 8230/8530 auto-focus function call. Here is my code:

Code: [Select]

' Call the auto focus EIKS function
itest& = J8K_StartOMAutoFocus(Jeolhandle&)
Call JeolGetError(itest&, "JeolAutoFocusScan8x30")
If ierror Then Exit Sub

' Wait before calling get auto-focus status
Call MiscDelay(CDbl(RealTimeInterval!), Now)
If icancelauto Or ierror Then Exit Sub

' Wait for completion. 0: Idling; 1: Running
istatus% = 1
Do Until istatus% = 0
itest& = J8K_ReadOMAutoFocusStatus(Jeolhandle&, istatus%)
Call JeolGetError(itest&, "JeolAutoFocusScan8x30")
If ierror Then Exit Sub

Call MiscDelay(CDbl(RealTimeInterval!), Now)
If icancelauto Or ierror Then Exit Sub
Loop

Do you see any adjustable parameters for the auto-focus in the JEOL software?  If yes, what are they? If there are adjustable parameters you and/or I will have to ping JEOL to get them to provide an API call to allow us to set them from the EIKS interface.
john 

[Probeman]

All,
This is specific to the 8900/8200/8500 auto focus mechanism, but after one 8200 user mentioned that they were having issues with their auto-focus (in both PFE and the JEOL UNIX software). Paul Carpenter chimed in with the following interesting info:

If the autofocus on an 8200 is not working - this is the Carnegie autofocus unit - then it is likely a problem with the reflected light intensity or rotational alignment of the camera with the cross hairs. The Carnegie unit samples the x-axis part of the reflected light image and uses the magnitude of brightness at focus to solve for max. intensity. The fluoroscan meters on the front of the Carnegie unit can be switched to show x or y value and they should be similar and high up on the scale when at focus on a nice reflective sample. That is my expectation. There could be a software problem if you are having an error on the Jeol when you try to do an autofocus, and I don't know what that would be. You may want to check the unix hard drive to see if it has filled up (like if you do lots of mapping on samples you can't talk about).

Turns out he was able to fix things for now by increasing the optical light intensity (in PFE that is the ReflectedLightIntensity keyword in the Probewin.ini file).  But I suspect his Carnegie auto focus should get aligned eventually by a service engineer.
john