CA monitoring weirdness for status/severity

["Hogben, Colin H" <Colin.Hogben@ukaea.uk>]

Hi,
Here at JET, I'm developing bridges (both directions) between EPICS 
Channel Access and our home-grown Object Monitoring System.  I've come 
across what to me seems like unexpected behaviour, which I can 
demonstrate with standard CA tools.
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.  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

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

So is it undefined or not?  I find it surprising that the last output 
from camonitor should differ depending on when I start it.
Any illumination welcome!
--
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