Re: Software for fill-on-fill injection

[Mohan Ramanathan <mohan@aps.anl.gov>]

Mark:

I have been seeing the trafic on this topic.
But let me clarify a few things on this topic.

>     Folks,
> 
> I am trying to modify my tomography software to work with fill-on-fill
> injection.  What I need to do is the following:
> 
> - ~60 seconds before a fill, stop data taking frames and take a final 'flat
>   field' for normalization
> 
> - After the fill wait ~60 seconds, take another flat field and then continue
>   taking data frames
> 
> In order to implement this I need PVs which provide the following information:
> 
> - Next fill-on-fill injection will occur in N minutes
> 
> - Previous fill-on-fill injection completed N minutes ago
> 
> Obviously other PVs from which the above information can be derived would also
> be fine.  Is such information currently available?  I could not find it in the
> Web documentation.  If it is not available am I the only one who thinks it is
> important to have?
> 
>                                    Mark Rivers
> 
At this time all Fill-On-Fill is done manually.  The announcement is made on the 
PA system 10-15 minutes prior to commensement of fill-on-fill.
We can easily implement a few PV as per your requiremnts.  
This can be done so that when the operator starts the procedure for fill-on-fill 
we can start a fixed count down timer, which upon expiring will commense the 
actual injection.  

At the current time we have some PV which are used for top-up.

> My message related not to top-up mode, but to normal fill-on-fill operations.
> You are correct that the PVs listed above exist, however their values seem to
> be meaningless during normal operations.  For example, right now:
> S:TopUpCurrent = 0.26746392
> S:TopUpTime  = Feb 27, 2000 11:33:24
> S:TopUpInterval =  1.0000000
> 

'S:TopUpCurrent' is the shot injection current. This is the last injection shot 
fired and stored.
'S:TopUpTime' is the Time in Local time when the last injection shot was 
performed.  During fill-on-fill this will relate to the end of the injection.
'S:TopUpInterval'  this process variable is derived from the secs since epoch 
and is a whole number. So during top-up this will inform the time between 
injection shots.  
'S:TopUpIntervalAvg' is the average of 60 inejction shots. Under normal 
injection conditions this will be 0.5 seconds as our injection frequency is 2 
Hz.


In addition the following Process Variables are available for Top-Up:

Mt:TopUpTime2Inject.VAL Seconds remaining until injection (seconds).
Mt:TopUpWarning.VAL  10 second warning to injection.

More later.
mohan

-----------------------------------------------------------------
Mohan Ramanathan                      Beamline Operations  
mohan@aps.anl.gov                     Advanced Photon Source
(630)-252-3773                        Argonne National Laboratory
(630)-252-9350 (FAX)                  Argonne, IL 60439
-----------------------------------------------------------------