def read_attr(self, attr):
attr_name = attr.get_name()
self.debug_stream('[read_attr] attribute %s' % attr_name)
try:
epics.ca.use_initial_context()
ch_id = self.pv[attr_name][0]
# reading was requested on read_attr_hardware(): now get the data
value = epics.ca.get_complete(ch_id)
if value is None: # reading failed
attr.set_quality(PyTango.AttrQuality.ATTR_INVALID)
msg = 'Error reading attribute %s' % attr_name
self.error_stream(msg)
self._set_state(PyTango.DevState.ALARM, msg)
attr.set_value(value)
if self.PreserveTimestamp:
attr.set_date(PyTango.TimeVal(epics.ca.get_timestamp(ch_id)))
except Exception as e:
msg = 'Error reading attribute %s' % attr_name
self.error_stream('%s: %s' % (msg, str(e)))
self._set_state(PyTango.DevState.ALARM, msg)
PyTango.Except.throw_exception(
'Read error',
msg,
'%s.read_%s()' % (self.__class__.__name__, attr_name))
def set_date(self,timestamp):
if not isinstance(timestamp,PyTango.TimeVal):
timestamp=PyTango.TimeVal(timestamp)
self.time=timestamp
def __init__(self, date, value):
self.value = value
self.time = PyTango.TimeVal(date) if not isinstance(
date, PyTango.TimeVal) else date
