When calling functions that give you an overview of the entire BeamPath object such as show_devices, we should be prepared for devices to raise Exceptions. One disconnected device should not prevent an operator from seeing the overview. These devices should instead report an Error state.
Current Behavior
In [2]: mfx_beampath.show_devices()
/reg/g/pcds/pyps/conda/py36/envs/pcds-0.6.0/lib/python3.6/site-packages/epics/ca.py:1330: UserWarning: ca.get('STPR:XRT1:1:SH2_PPSSUM') timed out after 1.00 seconds.
...
ValueError: None is not a valid state for sh2. Valid state names are: ['Unknown', 'IN', 'OUT'], and their corresponding values are [0, 1, 2].
This was noticed today while the FEE gateway was overloaded.
Expected Behavior
When calling functions that give you an overview of the entire
BeamPathobject such asshow_devices, we should be prepared for devices to raise Exceptions. One disconnected device should not prevent an operator from seeing the overview. These devices should instead report anErrorstate.Current Behavior
This was noticed today while the FEE gateway was overloaded.
Full ELog post -> https://pswww.slac.stanford.edu/apps/portal/index.php?exper_id=794&app=elog:search¶ms=message:381604
Possible Solution
try / except