class ExampleComboPositioner(Device, PositionerBase):
"""
A rewrite of ExamplePositioner that shows off the combobox.
LCLS uses a few "positioner" objects that move to named strings
instead of floating point positions, and this facilitates that
behavior.
"""
user_readback = Cpt(Signal, value='OUT', kind='hinted')
user_setpoint = Cpt(Signal, value='Unknown')
motor_is_moving = Cpt(Signal, value=False)
stop = None
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._status = None
self._status_ready_event = threading.Event()
enums = ('Unknown', 'OUT', 'TARGET1', 'TARGET2')
self.user_readback.enum_strs = enums
self.user_setpoint.enum_strs = enums
def set(self, position):
self._status_ready_event = threading.Event()
self.user_setpoint.put(position)
self._status_ready_event.wait()
return self._status
@user_setpoint.sub_value
def _start_motion_thread(self, value, **kwargs):
self._status = StatusBase()
self._status_ready_event.set()
if value == 'Unknown':
self._status.set_exception(
RuntimeError('Unknown not a valid target state'))
else:
td = threading.Thread(target=self._motion_thread)
td.start()
def _motion_thread(self):
self.motor_is_moving.put(True)
self.user_readback.put('Unknown')
time.sleep(3)
self.user_readback.put(self.user_setpoint.get())
self.motor_is_moving.put(False)
self._status.set_finished()
class ExamplePositioner(Device, PositionerBase):
"""
An example in-software positioner that works with the positioner widget.
This behaves more or less like you'd expect a real motor to behave.
"""
user_readback = Cpt(Signal,
value=0.0,
kind='hinted',
metadata={'precision': 3})
user_setpoint = Cpt(Signal, value=0.0)
low_limit_switch = Cpt(Signal, value=False)
high_limit_switch = Cpt(Signal, value=False)
low_limit_travel = Cpt(Signal, value=-10.0)
high_limit_travel = Cpt(Signal, value=10.0)
velocity = Cpt(Signal, value=1.0)
acceleration = Cpt(Signal, value=1.0)
motor_is_moving = Cpt(Signal, value=False)
error_message = Cpt(Signal, value='')
cause_error = Cpt(Signal, value='')
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._status = None
self._status_ready_event = threading.Event()
def set(self, position):
self._status_ready_event.clear()
self.user_setpoint.put(position)
self._status_ready_event.wait()
return self._status
@user_setpoint.sub_value
def _start_motion_thread(self, value, **kwargs):
self.stop(success=True)
self._status = StatusBase()
self._status_ready_event.set()
td = threading.Thread(target=self._motion_thread)
td.start()
def _motion_thread(self):
self.motor_is_moving.put(True)
while not self._status.done:
self._step_position()
self.motor_is_moving.put(False)
def _step_position(self):
time_step = 0.1
noise_factor = 0.1
noise = noise_factor * random.uniform(-1, 1)
dist = self.user_setpoint.get() - self.user_readback.get()
velo = self.velocity.get() * (1 + noise)
step = velo * time_step
if abs(dist) < step:
self.user_readback.put(self.user_setpoint.get() + noise / 10)
self._status.set_finished()
elif dist > 0:
self.user_readback.put(self.user_readback.get() + step)
elif dist < 0:
self.user_readback.put(self.user_readback.get() - step)
time.sleep(time_step)
def stop(self, success=False):
if self._status is not None and not self._status.done:
if success:
self._status.set_finished()
else:
self._status.set_exception(RuntimeError('Move Interrupted'))
@user_readback.sub_value
def _update_position(self, value, **kwargs):
if self.low_limit_travel.get() or self.high_limit_travel.get():
bot_hit = value <= self.low_limit_travel.get()
top_hit = value >= self.high_limit_travel.get()
self.low_limit_switch.put(bot_hit)
self.high_limit_switch.put(top_hit)
@low_limit_switch.sub_value
@high_limit_switch.sub_value
def _limit_hit(self, value, **kwargs):
if value:
self.stop(success=True)
def clear_error(self):
self.error_message.put('')
@cause_error.sub_value
def _cause_error(self, value, **kwargs):
self.error_message.put(value)