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<== Date ==> <== Thread ==>

Subject: Re: 5 counts in 1 hour
From: Andrew Johnson <anj@aps.anl.gov>
To: "Southern, Tim" <t1o@ornl.gov>, "tech-talk@aps.anl.gov" <tech-talk@aps.anl.gov>
Date: Thu, 7 Jan 2016 16:55:39 -0600
On 01/07/2016 04:41 PM, Southern, Tim wrote:
> The way a db record interprets the value of a waveform/compress VAL
> field is not the same as when one performs a caget in a terminal?
> In a terminal, ( $>> caget somePVwaveform ) returns the entire array of
> values for the record. When called inside the CALC record, only the
> first item of the array is returned?

The record types that can only handle a single element effectively do
the equivalent of 'caget -#1 pvname', thus they will only see and use
the first element if you point them to a PV that contains an array.

If your IOC is running Base-3.15.x you can use a server-side filter in
the PV name to request the value of some element other than the first,
but with Base-3.14 you only ever get the first element.

- Andrew

-- 
There are only two hard problems in distributed systems: 2. Exactly-once
delivery 1. Guaranteed order of messages 2. Exactly-once delivery
 -- Mathias Verraes

References:
5 counts in 1 hour Southern, Tim
Re: 5 counts in 1 hour Andrew Johnson
Re: 5 counts in 1 hour Southern, Tim

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