class Watchman:
cbid = None
retries = 3
def __init__(self, door_state, voltage_read, voltage_write):
self.door_state = EpicsSignalRO(door_state)
self.mesh_voltage = EpicsSignal(voltage_read, write_pv=voltage_write)
print('Using door pv {}'.format(door_state))
def start(self):
"""Sets up self.callback to be run when door state changes"""
# Make sure we don't start 2 processes
self.stop()
print('Starting door watcher')
self.door_state.subscribe(self.callback)
def callback(self, old_value=None, value=None, **kwargs):
"""To be run every time the door state changes"""
print('Door PV changed from {} to {}'.format(old_value, value))
if old_value == 1 and value == 0:
print('Zeroing the mesh voltage because door was opened')
# Let's retry a few times in case of a network error
for i in range(self.retries):
try:
self.mesh_voltage.put(0)
except Exception:
pass
def stop(self):
"""Shutdown the watcher"""
if self.cbid is not None:
print('Stopping door watcher')
self.door_state.unsubscribe(self.cbid)
self.cbid = None
Will become current actual position array, gets filled by EpicsSignalRO
timestamp : float
Will become current timestamp for actual position array,
i.e ``timestamp`` of ``value``
"""
# Get Current array and associated timestamp
# Assuming timestamp corresponds to last point in array, is this an OK
# assumption?
# Only taking new arrays, check for update
comparison = value == old_value
if not comparison.all():
enc_vals.append(value)
timestamps.append(timestamp) # System time may be better, why?
cbid = sig.subscribe(cb) # callback id
print('Acquiring Data From PV %s ...' % enc_pv)
print('Please wait %s s' % acq_time)
time.sleep(acq_time - (EPICS_SAMPLE_TIME / 2)) # wait time found by experiment
# cb seems to always finish its cycle before exiting, waiting exact acq_time
# seems to always give an extra array
# sig.unsubscribe not working in script, causes seg fault
sig.destroy() # This has desired behavior
print('Data Acquired, generated file %s' % outfile_name)
# Inspecting with datetime.fromtimestamp(current_timestamp), this appears
# to be correct
# Should have list [arr_1, arr_2, ... , arr_(acq_time/EPICS_SAMPLE_TIME)]
# Need to covert to arrays of tvals that match up with enc_vals
for i in range(len(enc_vals)):
curr_time_array = np.zeros(enc_vals[i].size)