Re: Fanout and asub interaction issues

["Wang, Andrew via Tech-talk" <tech-talk at aps.anl.gov>]

Hi Tim,

I just realized I made a typo. I had them as aai records not aao as my pseudo code contained. The aai records are getting the string via a StreamDevice protocol file. 

I changed them to waveform but it didn’t work.

Thoughts?

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From: Mooney, Tim M. <mooney at anl.gov>
Sent: Friday, April 16, 2021 8:41 PM
To: EPICS tech-talk <tech-talk at aps.anl.gov>; Wang, Andrew <wang126 at llnl.gov>
Subject: Re: Fanout and asub interaction issues

 

Hi Andrew,

I would have expected your database to work.  Do the aao records use asynchronous device support?  How is an aao record getting a string?

In any case, if you have the calc module, you could replace the fanout with a sseq record, which can wait for completion between output links.  I would do it like this:

record(sseq, "sseq_rec") {

    field(LNK1, "aao_rec_1.PROC CA")

    field(WAIT1, "After2")

    field(LNK2, "aao_rec_2.PROC CA")
    field(WAIT2, "Wait")

    field(LNK3, "asub_rec.PROC PP")

}

This will process aao_rec_1 and aao_rec_2, wait for them both to finish, and then process asub_rec.

I would not use aao records to hold strings.  I would use waveform records with FTVL=="CHAR".

Tim Mooney (mooney at anl.gov) (630)252-5417
Beamline Controls Group (www.aps.anl.gov)
Advanced Photon Source, Argonne National Lab

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From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Wang, Andrew via Tech-talk <tech-talk at aps.anl.gov>
Sent: Friday, April 16, 2021 9:29 PM
To: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: Fanout and asub interaction issues

 

All,

 

I am encountering an interesting problem and would again appreciate your insights.

 

Essentially, I have a fanout record and asub record that resemble the following pseudocode:

 

record(fanout, “fanout_rec”)

{

              field(SCAN, “Passive”)

              field(LNK0, “aao_rec_1”)

              field(LNK1, “aao_rec_2”)

              field(LNK2, “asub_rec”)

}

 

record(asub, “asub_rec”)

{

              field(SCAN, “Passive”)

              field(SNAM, “c_code”)

              field(INPA, “aao_rec_1”)

              field(FTVA, “CHAR”)

              field(NOA, 2048)

              field(INPB, “aao_rec_2”)

              field(FTVB, “DOUBLE”)

              field(NOB, 2048)

}

 

My goal was to first process the first two aao records so they contain the most up-to-date values before processing “asub_rec”. When I attempt to retrieve the values from both aao records within “c_code”, it is getting previous values that they contained prior to their latest processing.

 

For instance, if “aao_rec_1” contained “hello”, then when I print out “(CHAR*)prec->a” in “c_code”, it prints out nothing. But when I process it again, but with a different value, I print out “hello”, rather than the latest value it has.

 

I’m beginning to think it might be better to use the PP flag for INPA and INPB like this:

 

record(asub, “asub_rec”)

{

              field(SCAN, “Passive”)

              field(SNAM, “c_code”)

              field(INPA, “aao_rec_1 PP”)

              field(FTVA, “CHAR”)

              field(NOA, 2048)

              field(INPB, “aao_rec_2 PP”)

              field(FTVB, “DOUBLE”)

              field(NOB, 2048)

}

 

Any thoughts or suggestions?

 

Andy