How to use the ophyd.utils.epics_pvs.raise_if_disconnected function in ophyd

    @raise_if_disconnected
    def setpoint_alarm_status(self):
        """Setpoint PV status"""
        with self._lock:
            status = self._write_pv.status
            if status is None:
                return None
            return AlarmStatus(status)

    @raise_if_disconnected
    def limits(self):
        '''The read PV limits'''

        # This overrides the base limits
        with self._lock:
            pv = self._read_pv
            pv.get_ctrlvars()
            return (pv.lower_ctrl_limit, pv.upper_ctrl_limit)

    @raise_if_disconnected
    def setpoint_alarm_status(self):
        """Setpoint PV status"""
        with self._lock:
            status = self._write_pv.status
            if status is None:
                return None
            return AlarmStatus(status)

    @raise_if_disconnected
    def alarm_status(self):
        """PV status"""
        with self._lock:
            status = self._read_pv.status
            if status is None:
                return None
            return AlarmStatus(status)

    @raise_if_disconnected
    def timestamp(self):
        '''Timestamp of readback PV, according to EPICS'''
        with self._lock:
            if not self._read_pv.auto_monitor:
                # force updating the timestamp when not using auto monitoring
                self._read_pv.get_timevars()
            return self._read_pv.timestamp

    @raise_if_disconnected
    def read(self):
        """Read the signal and format for data collection

        Returns
        -------
        dict
            Dictionary of value timestamp pairs
        """

        return {self.name: {'value': self.value,
                            'timestamp': self.timestamp}}

    @raise_if_disconnected
    def alarm_severity(self):
        """PV alarm severity"""
        with self._lock:
            severity = self._read_pv.severity
            if severity is None:
                return None
            return AlarmSeverity(severity)

    @raise_if_disconnected
    def setpoint_ts(self):
        '''Timestamp of setpoint PV, according to EPICS'''
        with self._lock:
            if not self._write_pv.auto_monitor:
                # force updating the timestamp when not using auto monitoring
                self._write_pv.get_timevars()
            return self._write_pv.timestamp

    @raise_if_disconnected
    def alarm_severity(self):
        """PV alarm severity"""
        with self._lock:
            severity = self._read_pv.severity
            if severity is None:
                return None
            return AlarmSeverity(severity)

    @raise_if_disconnected
    def timestamp(self):
        '''Timestamp of readback PV, according to EPICS'''
        with self._lock:
            if not self._read_pv.auto_monitor:
                # force updating the timestamp when not using auto monitoring
                self._read_pv.get_timevars()
            return self._read_pv.timestamp