def decode(self, pv):
"""Decodes an epics PV object into a TaurusValue, and also updates other
properties of the Attribute object
"""
attr_value = TaurusAttrValue()
if not pv.connected:
attr_value.error = ChannelAccessException('PV "%s" not connected' %
pv.pvname)
return attr_value
v = pv.value
# type
try:
self.type = Dbr2TaurusType[pv.ftype]
except KeyError:
raise ValueError('Unsupported epics type "%s"' % pv.type)
# writable
self.writable = pv.write_access
# data_format
if numpy.isscalar(v):
self.data_format = DataFormat._0D
else:
self.data_format = DataFormat(len(numpy.shape(v)))
# units and limits support
if self.type in (DataType.Integer, DataType.Float):
v = Quantity(v, pv.units)
self._range = self.__decode_limit(pv.lower_ctrl_limit,
pv.upper_ctrl_limit)
self._alarm = self.__decode_limit(pv.lower_alarm_limit,
pv.upper_alarm_limit)
self._warning = self.__decode_limit(pv.lower_warning_limit,
pv.upper_warning_limit)
# rvalue
attr_value.rvalue = v
# wvalue
if pv.write_access:
attr_value.wvalue = v
# time
if pv.timestamp is None:
attr_value.time = TaurusTimeVal.now()
else:
attr_value.time = TaurusTimeVal.fromtimestamp(pv.timestamp)
# quality
if pv.severity > 0:
attr_value.quality = AttrQuality.ATTR_ALARM
else:
attr_value.quality = AttrQuality.ATTR_VALID
return attr_value
def decode(self, pv):
"""Decodes an epics PV object into a TaurusValue, and also updates other
properties of the Attribute object
"""
attr_value = TaurusAttrValue()
if not pv.connected:
attr_value.error = ChannelAccessException('PV "%s" not connected' %
pv.pvname)
return attr_value
v = pv.value
# type
try:
self.type = Dbr2TaurusType[pv.ftype]
except KeyError:
raise ValueError('Unsupported epics type "%s"' % pv.type)
# writable
self.writable = pv.write_access
# data_format
if numpy.isscalar(v):
self.data_format = DataFormat._0D
else:
self.data_format = DataFormat(len(numpy.shape(v)))
# units and limits support
if self.type in (DataType.Integer, DataType.Float):
v = Quantity(v, pv.units)
self._range = self.__decode_limit(pv.lower_ctrl_limit,
pv.upper_ctrl_limit)
self._alarm = self.__decode_limit(pv.lower_alarm_limit,
pv.upper_alarm_limit)
self._warning = self.__decode_limit(pv.lower_warning_limit,
pv.upper_warning_limit)
# rvalue
attr_value.rvalue = v
# wvalue
if pv.write_access:
attr_value.wvalue = v
# time
if pv.timestamp is None:
attr_value.time = TaurusTimeVal.now()
else:
attr_value.time = TaurusTimeVal.fromtimestamp(pv.timestamp)
# quality
if pv.severity > 0:
attr_value.quality = AttrQuality.ATTR_ALARM
else:
attr_value.quality = AttrQuality.ATTR_VALID
return attr_value
def read(self, cache=True):
if cache and self._last_value is not None:
return self._last_value
dev = self.getParentObj()
# each time we need to open and close the file, otherwise the
# file content is not updated
with h5py.File(dev.filename) as h5file:
data = h5file.get(self._attr_name)
if data is None:
msg = "Object %s does not exist" % self._attr_name
raise TaurusException(msg)
# we need to decode and copy the data while the file is still opened
rvalue = self.decode(data)
value = TaurusAttrValue()
value.rvalue = rvalue
value.time = TaurusTimeVal.now()
self._last_value = value
return value
def read(self, cache=True):
"""Returns the value of the attribute.
:param cache: (bool) If True (default), the last calculated value will
be returned. If False, the referenced values will be re-
read.
:return: TaurusAttrValue
"""
if cache and self._last_value is not None:
return self._last_value
dev = self.getParentObj()
self.handler.setFilename(dev.filename)
data_frame = self.handler.parseAttrName(self._attr_name)
value = TaurusAttrValue()
value.rvalue = self.decode(data_frame)
value.time = TaurusTimeVal.now()
self._last_value = value
return value
