EPICS Proxy example¶

The epics proxy should provide methods that look the same as those in pyepics https://cars9.uchicago.edu/software/python/pyepics3/

In [1]:

# Useful for debugging
%load_ext autoreload
%autoreload 2

# Useful for debugging %load_ext autoreload %autoreload 2

In [2]:

from lcls_live.epics import epics_proxy
import os

from lcls_live.epics import epics_proxy import os

In [3]:

epics = epics_proxy('data/epics_snapshot_2018-03-06T15:21:15.000000-08:00.json', verbose=True)

epics = epics_proxy('data/epics_snapshot_2018-03-06T15:21:15.000000-08:00.json', verbose=True)

Loaded data/epics_snapshot_2018-03-06T15:21:15.000000-08:00.json with 2065 PVs

In [4]:

# Data is kept internally as a dict in .pvdata:
list(epics.pvdata)[0:10]

# Data is kept internally as a dict in .pvdata: list(epics.pvdata)[0:10]

Out[4]:

['ACCL:IN20:350:FUDGE',
 'ACCL:LI21:180:L1X_S_AV',
 'ACCL:LI21:180:L1X_S_PV',
 'ACCL:LI21:1:FUDGE',
 'ACCL:LI21:1:L1S_S_PV',
 'ACCL:LI22:1:FUDGE',
 'ACCL:LI24:100:KLY_PDES',
 'ACCL:LI24:200:KLY_PDES',
 'ACCL:LI24:300:KLY_PDES',
 'ACCL:LI25:1:FUDGE']

In [5]:

# caget fetches from .pvdata
epics.caget('KLYS:LI21:11:ENLD')

# caget fetches from .pvdata epics.caget('KLYS:LI21:11:ENLD')

Out[5]:

115.836

In [6]:

# caput writes to .pvdata
epics.caput('KLYS:LI21:11:ENLD', 3)
epics.caget('KLYS:LI21:11:ENLD')

# caput writes to .pvdata epics.caput('KLYS:LI21:11:ENLD', 3) epics.caget('KLYS:LI21:11:ENLD')

Out[6]:

3

In [7]:

# PV
pv = epics.PV('KLYS:LI21:11:ENLD')
pv.get()

# PV pv = epics.PV('KLYS:LI21:11:ENLD') pv.get()

PV for KLYS:LI21:11:ENLD

Out[7]:

3

In [8]:

# caget_many 
epics.caget_many(['KLYS:LI21:11:ENLD',
 'ACCL:LI21:1:L1S_S_PV',
 'KLYS:LI21:11:PDES',
 'KLYS:LI21:11:SWRD',
 'KLYS:LI21:11:STAT',
 'KLYS:LI21:11:HDSC',
 'KLYS:LI21:11:DSTA',
 'KLYS:LI21:11:BEAMCODE1_STAT',
 'ACCL:LI21:180:L1X_S_AV',
 'ACCL:LI21:180:L1X_S_PV'])

# caget_many epics.caget_many(['KLYS:LI21:11:ENLD', 'ACCL:LI21:1:L1S_S_PV', 'KLYS:LI21:11:PDES', 'KLYS:LI21:11:SWRD', 'KLYS:LI21:11:STAT', 'KLYS:LI21:11:HDSC', 'KLYS:LI21:11:DSTA', 'KLYS:LI21:11:BEAMCODE1_STAT', 'ACCL:LI21:180:L1X_S_AV', 'ACCL:LI21:180:L1X_S_PV'])

Out[8]:

[3,
 -26.12494033014282,
 -24.5,
 0,
 1,
 1048577.0,
 [1610612738.0, 528640.0],
 1.0,
 20.01551950520014,
 -159.9562692633193]

In [9]:

# Non-epics routine to save .pvdata to a JSON file
epics.save(filename='test.json')

# Non-epics routine to save .pvdata to a JSON file epics.save(filename='test.json')

Saved test.json

In [10]:

# Corresponding load routine
epics.load(filename='test.json')

# Corresponding load routine epics.load(filename='test.json')

Loaded test.json with 2065 PVs

In [11]:

# Cleanup
os.remove('test.json')

# Cleanup os.remove('test.json')

Nested proxies¶

In [12]:

# Start with a 'base' source of epics data
epics0 = epics_proxy('data/epics_snapshot_2018-03-06T15:21:15.000000-08:00.json', verbose=True)

# Make another proxy
epics1 = epics_proxy('cache.json', epics=epics0, verbose=True)

# Start with a 'base' source of epics data epics0 = epics_proxy('data/epics_snapshot_2018-03-06T15:21:15.000000-08:00.json', verbose=True) # Make another proxy epics1 = epics_proxy('cache.json', epics=epics0, verbose=True)

Loaded data/epics_snapshot_2018-03-06T15:21:15.000000-08:00.json with 2065 PVs

In [13]:

# Get a value
epics1.caget('KLYS:LI21:11:ENLD')

# Get a value epics1.caget('KLYS:LI21:11:ENLD')

Error: pv not cached: KLYS:LI21:11:ENLD
Loading from epics

Out[13]:

115.836

In [14]:

# This is the internal data
epics1.pvdata

# This is the internal data epics1.pvdata

Out[14]:

{'KLYS:LI21:11:ENLD': 115.836}

In [15]:

epics1.caget_many(['KLYS:LI21:11:ENLD', 'KLYS:LI21:11:DSTA'])

epics1.caget_many(['KLYS:LI21:11:ENLD', 'KLYS:LI21:11:DSTA'])

Out[15]:

[115.836, [1610612738.0, 528640.0]]

In [16]:

# This is the internal data
epics1.pvdata

# This is the internal data epics1.pvdata

Out[16]:

{'KLYS:LI21:11:ENLD': 115.836}

In [17]:

# Save to JSON
epics1.save()

# Save to JSON epics1.save()

Saved cache.json

In [18]:

# Cleanup
os.remove('cache.json')

# Cleanup os.remove('cache.json')