RE: Passive Scanning processing

["Dalesio, Leo" <dalesio@bnl.gov>]

The link is owned by the AI record. The AI record is not referencing the Calc record.

Putting to the AI record – does not affect the Calc record as the AI record does not know how to reference the Calc record.

 

If you want the Calc to process when the AI is processed –

1)      use the forward link in the AI record – FLNK – enter the Calc record into it.

2)      Use the CPP option on the Calc records reference to the AI record (this causes a channel access monitor to process the Calc record whenever the AI record changes (note – not any time it is processed – any time it changes VAL).

Chapter 2 of the record reference explains this. (At least it used to be chapter two.)

 

From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf Of Diego Sanz
Sent: Tuesday, December 11, 2012 9:44 AM
To: tech-talk@aps.anl.gov
Subject: Passive Scanning processing

 

My Doubt is about the processing of a pasive Record with an input Link PP, with another passive record connected to.  In point 1. and 1.3  in the EPICS Record Reference Manual comes information related to it. I understand that every passive record is processed when I change its VAL. e.g.,  I've got the next record in my Db

 

record(ai,inp0){

field(SCAN,"Passive")

}

 

...then I run the IOC, and every time I change the VAL, (e.g., with caput command: caput inp0 124) , I can see with camonitor command that the PV value is changing.

 

Now we connect this Record to the next record:

 

record (calc,calcinp){

field(SCAN,"PAssive")

field(INPA," inp0 PP")

field(CALC,"A+45")

}

 

What I understand from reference manual, is that a passive record with a PP Link (in this case calcinp) with another passive record connected to (in this case inp0), is processed if the other record (inp0) is processed, and I can make  inp0 to be processed executing the command "caput inp0 198".

 

But the result is that every time I change the value of inp0 with the caput command, the calcinp record is not processed...why?

 

Thanks for the answers