Make PSS Shutter devices more flexible for different beamlines

[canismarko]

The ApsPssShutter does not match our beamline configuration (25-ID).

The open signal is created as {PREFIX}_Open but should be {PREFIX}_OPEN_EPICS to work on our hardware. The close signal is the same (but with "Close", etc.).

Here is the subclass of ApsPssShutterWithStatus that matches our hardware: https://github.com/spc-group/haven/blob/main/haven/instrument/shutter.py

[prjemian]

Also, there are no unit tests on the shutter classes.

[prjemian]

This code should become more flexible:

apstools/apstools/devices/shutters.py

Lines 406 to 407 in 199c178

	open_signal = Component(EpicsSignal, "Open")
	close_signal = Component(EpicsSignal, "Close")

[prjemian]

@canismarko - Looking at the haven code, this looks like an unusual API signature. I'm expecting prefix to be the first argument, such as:

apstools/apstools/devices/shutters.py

Line 495 in 199c178

def __init__(self, prefix, state_pv, *args, **kwargs):

I plan to make the API here similar, allowing for close_pv and open_pv as kwargs.

[prjemian]

As in:

class ApsPssShutter(ShutterBase):

    # ...

    open_signal = FormattedComponent(EpicsSignal, "{self.open_pv}")
    close_signal = FormattedComponent(EpicsSignal, "{self.close_pv}")

    def __init__(self, prefix, *args, close_pv=None, open_pv=None, **kwargs):
        self.open_pv = open_pv or f"{prefix}Open"
        self.close_pv = close_pv or f"{prefix}Close"
        # TODO" ?? what about prefix if open_pv and/or close_pv are not None ??
        super().__init__(prefix, *args, **kwargs)

    # ...

The ApsPssShutterWithStatus() class does not need changes since it passes close_pv and open_pv as unnamed kwargs to the super() class.

[prjemian]

Shutter might be in unknown state. CI failed for that:

/home/runner/work/apstools/apstools/apstools/devices/tests/test_shutters.py:96: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

shutter = EpicsMotorShutter(prefix='gp:m16', name='shutter', read_attrs=['busy', 'signal', 'signal.user_readback', 'signal.user_...signal', 'signal.user_offset', 'signal.user_offset_dir', 'signal.velocity', 'signal.acceleration', 'signal.motor_egu'])

    def operate_shutter(shutter):
        shutter.open()
        timed_pause()
>       assert shutter.state == "open"
E       AssertionError: assert 'unknown' == 'open'
E         - open
E         + unknown