Difference between EpicsMotor from other positioners

[prjemian]

The EpicsMotor class has a notable inconsistency from other positioners. The names for readback and setpoint components differ from all other positioners.

ophyd/ophyd/epics_motor.py

Lines 42 to 44 in 1e5f037

	# position
	user_readback = Cpt(EpicsSignalRO, ".RBV", kind="hinted", auto_monitor=True)
	user_setpoint = Cpt(EpicsSignal, ".VAL", limits=True, auto_monitor=True)

ophyd/ophyd/pv_positioner.py

Line 587 in 1e5f037

setpoint = Cpt(EpicsSignal, "", kind="hinted")

ophyd/ophyd/pseudopos.py

Lines 51 to 52 in 1e5f037

	readback = Cpt(AttributeSignal, attr="position", kind=Kind.hinted)
	setpoint = Cpt(AttributeSignal, attr="target", kind=Kind.normal)

ophyd/ophyd/tests/fake_motor_ioc.py

Lines 7 to 8 in 1e5f037

	setpoint = pvproperty(value=0.0, precision=1)
	readback = pvproperty(value=0.0, read_only=True, precision=1)

I'm sure the user_ prefix used in EpicsMotor is inherited from the EPICS motor record which has raw, dial, and user coordinates. But NO bluesky users (maybe there is a rare exception) use motors with dial coordinates.

Not only is this confusing for newer Bluesky users, this leads to special-case programming when handling positioners v. motors.

Is there a way to resolve this inconsistency that remains backwards-compatible? Adding a synonym?

 # position 
    readback = user_readback = Cpt(EpicsSignalRO, ".RBV", kind="hinted", auto_monitor=True) 
    setpoint = user_setpoint = Cpt(EpicsSignal, ".VAL", limits=True, auto_monitor=True) 

[tacaswell]

I think adding the alias is a good idea, but would probably have to do it with a property to avoid the Componet getting picked up twice.

[prjemian]

I'll try that locally before initiating a PR.