Hi Colin,
I can reproduce your observations.
I loaded the test record you listed into an "example" IOC.
This is the record after booting the IOC:
epics> dbpr chah:ao 10
ACKS: NO_ALARM ACKT: YES ADEL: 0 ALST: 0
AOFF: 0 ASG: ASLO: 0 ASP: (nil)
BKPT: 00 DESC: DISA: 0 DISP: 0
DISS: NO_ALARM DISV: 1 DOL:CONSTANT DPVT: (nil)
DRVH: 0 DRVL: 0 DSET: 0x7f34c51bf9a0
DTYP: Soft Channel EGU: EGUF: 0 EGUL: 0
EOFF: 0 ESLO: 1 EVNT: FLNK:CONSTANT 0
HHSV: NO_ALARM HIGH: 10 HIHI: 0 HOPR: 0
HSV: NO_ALARM HYST: 0 INIT: 1
IVOA: Continue normally IVOV: 0 LALM: 0
LBRK: 0 LCNT: 0 LINR: NO CONVERSION LLSV: NO_ALARM
LOLO: 0 LOPR: 0 LOW: 0 LSET: 0x23c3040
LSV: NO_ALARM MDEL: 0
MLIS: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
MLOK: 70 40 3c 02 00 00 00 00 MLST: 0 NAME: chah:ao
NSEV: NO_ALARM NSTA: NO_ALARM OIF: Full OMOD: 0
OMSL: supervisory ORAW: 0 ORBV: 0 OROC: 0
OUT:CONSTANT OVAL: 0 PACT: 0 PBRK: (nil)
PHAS: 0 PINI: NO PPN: (nil) PPNR: (nil)
PREC: 0 PRIO: LOW PROC: 0 PUTF: 0
PVAL: 0 RBV: 0 RDES: 0x236a220 ROFF: 0
RPRO: 0 RSET: 0x7f34c51be5a0 RVAL: 0
SCAN: Passive SDIS:CONSTANT SEVR: INVALID SIML:CONSTANT
SIMM: NO SIMS: NO_ALARM SIOL:CONSTANT SPVT: (nil)
STAT: UDF TIME: <undefined> TPRO: 0 TSE: 0
TSEL:CONSTANT UDF: 1 UDFS: INVALID VAL: 0
I then monitor the HIGH field as you did an get the same result:
corvette:mca/iocBoot/iocAmptek>camonitor chah:ao.HIGH
chah:ao.HIGH <undefined> 10 UDF INVALID
I then put 11 to the HIGH field:
corvette:~>caput chah:ao.HIGH 11
Old : chah:ao.HIGH 10
New : chah:ao.HIGH 11
The camonitor program sees the new value:
chah:ao.HIGH <undefined> 11 UDF INVALID
I then do dbpr again at the IOC prompt:
epics> dbpr chah:ao 10
ACKS: NO_ALARM ACKT: YES ADEL: 0 ALST: 0
AOFF: 0 ASG: ASLO: 0 ASP: (nil)
BKPT: 00 DESC: DISA: 0 DISP: 0
DISS: NO_ALARM DISV: 1 DOL:CONSTANT DPVT: (nil)
DRVH: 0 DRVL: 0 DSET: 0x7f34c51bf9a0
DTYP: Soft Channel EGU: EGUF: 0 EGUL: 0
EOFF: 0 ESLO: 1 EVNT: FLNK:CONSTANT 0
HHSV: NO_ALARM HIGH: 11 HIHI: 0 HOPR: 0
HSV: NO_ALARM HYST: 0 INIT: 0
IVOA: Continue normally IVOV: 0 LALM: 0
LBRK: 0 LCNT: 0 LINR: NO CONVERSION LLSV: NO_ALARM
LOLO: 0 LOPR: 0 LOW: 0 LSET: 0x23c3040
LSV: NO_ALARM MDEL: 0
MLIS: 20 8e 03 b0 34 7f 00 00 20 8e 03 b0 34 7f 00 00 01 00 00 00
MLOK: 70 40 3c 02 00 00 00 00 MLST: 0 NAME: chah:ao
NSEV: NO_ALARM NSTA: NO_ALARM OIF: Full OMOD: 0
OMSL: supervisory ORAW: 0 ORBV: 0 OROC: 0
OUT:CONSTANT OVAL: 0 PACT: 0 PBRK: (nil)
PHAS: 0 PINI: NO PPN: (nil) PPNR: (nil)
PREC: 0 PRIO: LOW PROC: 0 PUTF: 0
PVAL: 0 RBV: 0 RDES: 0x236a220 ROFF: 0
RPRO: 0 RSET: 0x7f34c51be5a0 RVAL: 0
SCAN: Passive SDIS:CONSTANT SEVR: NO_ALARM SIML:CONSTANT
SIMM: NO SIMS: NO_ALARM SIOL:CONSTANT SPVT: (nil)
STAT: NO_ALARM TIME: 2017-08-07 08:12:32.703145990 TPRO: 0
TSE: 0 TSEL:CONSTANT UDF: 0 UDFS: INVALID
VAL: 0
Note that UDF is now 0 and there is a valid timestamp.
This is exactly the expected behavior, because if you look at the record reference manual here:
https://wiki-ext.aps.anl.gov/epics/index.php/RRM_3-14_Analog_Output
You will see that the HIGH field has the PP attribute. This means that writing to the HIGH field causes the record to process.
However, the HIGH field does not have Rec Proc Monitor, so writing to the HIGH field does not cause monitor events to be posted. So your original camonitor program does not get an event. However, if you run camonitor again it connects to the channel and does get the new timestamp and status.
corvette:~>camonitor chah:ao.HIGH
chah:ao.HIGH 2017-08-07 08:12:32.703146 11
Mark
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Hogben, Colin H
Sent: Monday, August 07, 2017 7:06 AM
To: Johnson, Andrew N.
Cc: [email protected]
Subject: Re: CA monitoring weirdness for status/severity
Hi Andrew,
Thanks for your response.
>> 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.
I'm coming at this from the CA protocol perspective, and I'm aware that
a CA_PROTO_EVENT_ADD response for TIME_DOUBLE contains status, severity
and value (and also timestamp).
> 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.
From the CA point of view, the .HIGH and .VAL are separate PVs; the
protocol has no knowledge of what "record" or other concept may lie
behind them. Even if the CA server is using some common status &
severity for multiple PVs, I'd still expect it to report the same status
& severity to all clients of any given PV.
>> 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?
Yes, quite sure. Did you try it? BTW I forgot to say that this is with
version 3.14.12.5 of base.
> The change to the metadata implies that someone did since they are now set so the record has been processed.
It looks to me as though writing to .HIGH causes the record to be processed.
I've just discovered that if I do a second write to .HIGH, the original
camonitor sees status=0 severity=0 and a valid timestamp when it
receives the new EVENT_ADD. As though they're lagging behind by one update.
> 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.
Hmm, if status & severity aren't reliable other than for .VAL, it looks
like I may have to apply some heuristics based on the PV name (eugh!).
--
Colin Hogben
Professional Software/Control Engineer
CODAS & IT Department
United Kingdom Atomic Energy Authority
Culham Science Centre
Abingdon
Oxfordshire
OX14 3DB
Tel : 01235 464948
Web: www.gov.uk/ukaea
- Replies:
- Re: CA monitoring weirdness for status/severity Hogben, Colin H
- References:
- CA monitoring weirdness for status/severity Hogben, Colin H
- Re: CA monitoring weirdness for status/severity Johnson, Andrew N.
- Re: CA monitoring weirdness for status/severity Hogben, Colin H
- Navigate by Date:
- Prev:
Re: CA monitoring weirdness for status/severity bob dalesio
- Next:
RE: CA monitoring weirdness for status/severity Mark Rivers
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
<2017>
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Re: CA monitoring weirdness for status/severity bob dalesio
- Next:
Re: CA monitoring weirdness for status/severity Hogben, Colin H
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
<2017>
2018
2019
2020
2021
2022
2023
2024
| 
·
Home
·
News
·
About
·
Base
·
Modules
·
Extensions
·
Distributions
·
Download
·