Re: PyEpics: Cannot connect to DEVICE

[Matt Newville via Tech-talk <tech-talk at aps.anl.gov>]

Hi Thomas, 

Sorry for the trouble.  Are you sure that it is necessary to set the EPICS_CA* environment variables in the Python script, or are those already set in the environment running your Python and PyCharm apps?    What are these variables set to when running the command-line interface in a Terminal shell?

It should be that

   C:>. caget PVNAME

and 

   C:> python -c "import epics ; print(epics.caget('PVNAME'))"

give the same result - the Python interpreter should inherit whatever EPICS_CA ADDR settings you have for the shell.  If that works, then try:

   C:> printenv

and grep (either with Posix commands or by hand) for EPICS_CA_ADDR.   

--Matt

On Thu, Jun 9, 2022 at 10:28 AM Thomas Feggeler via Tech-talk <tech-talk at aps.anl.gov> wrote:

Dear colleagues,

We have a new computer installation (Windows 10) with epics 7.0.4, python 3.6.4. When I try to connect with caget() directly over the command line to access a device, e.g.

Caget XXXX:XXXX:firmwarebuilddate

It immediately works.

When using pyepics over pycharm, or the python interpreter, the message „cannot connect to DEVICE“ is given out.

The Windows path variables are set, EPICS_CA_ADDR_LIST is set and imported into the pycharm environment.

In both pycharm and python console if I do the following:

import epics
import os
from epics import PV, caget, caput, cainfo
os.environ['EPICS_CA_ADDR_LIST'] = 'XXX.XXX.XXX.XXX'
os.environ['EPICS_CA_AUTO_ADDR_LIST'] = 'NO'
print(caget('XXXX:XXXX:firmwarebuilddate'))

The same error occurs.

I’d kindly ask for your help.

Thank you

Kind wishes

Thomas