PV status low, high, lolo, hihi always set to 0

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I am not able to set some value to the low, high, lolo, hihi status variables. 
In the example alarm_severity.py in the pcaspy-0.4.1/example directory the 
variables are set to not equal zero:

$ python alarm_severity.py

in another console cainfo does not show me any alarm values:

$ cainfo MTEST:RAND

MTEST:RAND
    State:            connected
    Host:             10.0.2.15:5064
    Access:           read, write
    Native data type: DBF_DOUBLE
    Request type:     DBR_DOUBLE
    Element count:    1

I also tried with pyepics on the ipython console:

In [1]: import epics
In [2]: pv=epics.PV('MTEST:RAND')
In [3]: print pv.info                                            
== MTEST:RAND  (native_double) ==
   value      = 0
   char_value = '0'
   count      = 1
   nelm       = 1
   type       = double
   units      = 
   precision  = 3
   host       = 10.0.2.15:5064
   access     = read/write
   status     = 17
   severity   = 3
   timestamp  = 1412767230.217 (2014-10-08 04:20:30.21738)
   upper_ctrl_limit    = 0.0
   lower_ctrl_limit    = 0.0
   upper_disp_limit    = 0.0
   lower_disp_limit    = 0.0
   upper_alarm_limit   = 0.0
   lower_alarm_limit   = 0.0
   upper_warning_limit = 0.0
   lower_warning_limit = 0.0
   PV is internally monitored, with 0 user-defined callbacks:
=============================

Tested with epics
base-3.14.12.3 and
base-3.14.12.4 and
base-3.15.0.2

swig2.0
Python 2.7.5+
ubuntu 13.10

Original issue reported on code.google.com by wernwa@gmail.com on 8 Oct 2014 at 2:07

[GoogleCodeExporter]

The first issue is a problem of alarm_severity.py. In myDriver.write method, it 
did not handle the write request of PV 'RAND'. I have committed a fix in the 
repository. Please check.

The second issue is more subtle. The low,high,lolo,hihi fields are currently 
only used to configure how to set alarm/severity status.  When reporting the 
various limits, the lolim, hilim fields are used instead. This creates the 
confusion. I would propose to use the following correspondence:
  upper_ctrl_limit and upper_disp_limit -> hilim
  lower_ctrl_limi and lower_disp_limit -> lolim
  upper_alarm_limit -> hihi
  lower_alarm_limit -> lolo
  upper_warn_limit -> high
  lower_warn_limit -> low

So an equivalent of the ao record of 
record(ao, "ao")
{
    field (LOLO, "-10")
    field (LLSV, "MAJOR")
    field (LOW,  "-5")
    field (LSV,  "MINOR")
    field (HIGH, "5")
    field (HSV,  "MINOR")
    field (HIHI, "10")
    field (HHSV, "MAJOR")
    field (LOPR, "-10")
    field (HOPR, "10")
    field (DRVL, "-10")
    field (DRVH,  "10")
}

could be configured as 
{
  'lolim': -10, 'hilim': 10,
  'lolo': -10, 'low':-5,
  'hihi': 10, 'high': 5
}

Original comment by xiaoqian...@gmail.com on 8 Oct 2014 at 7:30

• Changed state: Accepted

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[deleted comment]

[GoogleCodeExporter]

The above changes have been done in 0.5.1.b1. 

sudo pip install hg+http://code.google.com/p/pcaspy

I will release it if you confirm the fix.

Original comment by xiaoqian...@gmail.com on 9 Oct 2014 at 7:44

[GoogleCodeExporter]

hallo xiaoqian

With the new version the fields low,high,lolo,hihi are now displayed with 
pyepics:

In [3]: pv=epics.PV('MTEST:RAND')
In [4]: print pv.info
...
   upper_alarm_limit   = 10.0
   lower_alarm_limit   = -10.0
   upper_warning_limit = 5.0
   lower_warning_limit = -5.0
...

So i can confirm the changes! 

Yes, i was little bit confused by the amount of fields. Thanks for making it 
more clear.

Original comment by wernwa@gmail.com on 9 Oct 2014 at 9:03