def __init__(self, pvName=None, wait=True): """ Create an EPICS channel if pvName is specified, and optionally wait for connection. :param str pvName: An optional name of an EPICS Process Variable. :param bool wait: If wait is True and pvName is not None then this constructor will do a :meth:`CaChannel.CaChannel.searchw` on the PV. If wait is False and pvName ist not None then this constructor will do a :meth:`CaChannel.CaChannel.search` on the PV, and the user must subsequently do a :meth:`CaChannel.CaChannel.pend_io` on this or another :class:`epicsPV` or :class:`CaChannel` object. """ # Invoke the base class initialization self.callBack = callBack() CaChannel.__init__(self) if pvName is not None: if wait: self.searchw(pvName) else: self.search(pvName)