RE: CA monitoring weirdness for status/severity

[Mark Rivers <rivers@cars.uchicago.edu>]

>>  caput chah:ao.HIGH 11
>> and the camonitor spits out an update:
>>  chah:ao.HIGH                   <undefined> 11 UDF INVALID
> The value changes as you expect, but the record still hasn't processed or been given a value to define the VAL field, so it's still undefined and in UDF alarm.

>> However, if I start a new camonitor, I get
>>  gen-pub-11:~ $ camonitor chah:ao.HIGH
>>  chah:ao.HIGH                   2017-08-07 10:30:55.033976 11
> Are you sure you didn't also do a put to the VAL field in between? The change to the metadata implies that someone did since they are now set so the record has been processed.

The HIGH field has the PP attribute, so that is why the record processed.

Mark

________________________________________
From: tech-talk-bounces@aps.anl.gov [tech-talk-bounces@aps.anl.gov] on behalf of Johnson, Andrew N. [anj@aps.anl.gov]
Sent: Monday, August 07, 2017 5:51 AM
To: Hogben, Colin H
Cc: tech-talk@aps.anl.gov
Subject: Re: CA monitoring weirdness for status/severity

Hi Colin,

On Aug 7, 2017, at 10:58 AM, Hogben, Colin H <Colin.Hogben@ukaea.uk> wrote:
> First I start softIoc with the following database:
>
>  record(ao, "chah:ao") {
>    field(HIGH, 10)
>  }
>
> Next, I monitor the HIGH field:
>
>  gen-pub-11:~ $ camonitor chah:ao.HIGH
>  chah:ao.HIGH                   <undefined> 10 UDF INVALID
>
> My first surprise is that the HIGH field is reported as undefined, when it clearly has the value I configured.

There are 3 aspects to the camonitor output, and I think you're getting them confused. The <undefined> part means the record's time stamp is as yet unset, because it hasn't been processed yet. Similarly the UDF INVALID part means the record is still in a UDF alarm state because the VAL field hasn't been set. Note that the time stamp and alarm status and severity are related to the record as a whole, not to the particular field you're monitoring. You are getting the expected value for your field though, 10.

>  But it gets weirder.  I now do a

>  caput chah:ao.HIGH 11
>
> and the camonitor spits out an update:
>
>  chah:ao.HIGH                   <undefined> 11 UDF INVALID

The value changes as you expect, but the record still hasn't processed or been given a value to define the VAL field, so it's still undefined and in UDF alarm.

> However, if I start a new camonitor, I get
>
>  gen-pub-11:~ $ camonitor chah:ao.HIGH
>  chah:ao.HIGH                   2017-08-07 10:30:55.033976 11

Are you sure you didn't also do a put to the VAL field in between? The change to the metadata implies that someone did since they are now set so the record has been processed.

If you're going to be writing your own CA client code, you may not want to actually monitor the metadata for channels which aren't a record's VAL field, and make sure you're monitoring the right CA Event type as well.

HTH,

- Andrew

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