Dev4Tango Template Class¶
Contents
Description¶
This class provides several new features to TangoDevice implementations. By including log.Logger it also includes objects.Object as parent class. It allows to use call__init__(self, klass, *args, **kw) to avoid multiple inheritance from same parent problems. Therefore, use self.call__init__(PyTango.Device_4Impl,cl,name) instead of PyTango.Device_4Impl.__init__(self,cl,name)
It also allows to connect several devices within the same server avoiding the taurus.core dependency.
To enable it just inherit from it and call init_my_Logger right after getting the device properties:
class Agilent4UHV(Dev4Tango):
def __init__(self,cl,name):
self.call__init__(Dev4Tango,cl,name)
self.init_device()
def init_device(self):
self.get_device_properties(self.get_device_class())
self.init_my_Logger(self)
State Machine¶
The default state machine has been overriden to not allow qualities to modify the device state.
The is_Attr_allowed method provides a generic attribute disable when stat in INIT or UNKNOWN
Overriden methods are set_state, dev_state, State and get_state, default_status, is_Attr_allowed
Properties Initialization¶
| check_properties(props): | |
|---|---|
| verify that all properties have a proper value | |
| get_device_properties(class): | |
| it reads all properties and, if missing, updates the database with the default values | |
| update_properties(props): | |
| writes the default values to the database. | |
Child Attributes Update¶
TODO To be replaced by fandango.callbacks.EventListener API
API used by IonPump, PLCValve, VacuumGauge and PyStateComposer devices to periodically update the values of other devices using an internal background thread.
Methods:
| subscribe_external_attributes(device,attributes): | |
|---|---|
| unsubscribe_external_attributes: | |
| remove all | |
| write_external_attribute(device,attribute,data): | |
| launch_external_command(device,target,argin): | |
| update_external_attributes: | |
| thread main loop. | |
Helper Methods¶
| init_logger: | initialize the internal logger and self.error/warning/info/debug/trace methods. |
|---|---|
| getAttributeTime(any): | |
| extract epoch time from any of the different value objects in Tango | |
| getAttributeTemplate(name,type,rw,unit,format): | |
| Returns an Attr object ready to be inserted with self.add_attribute(&Attr,&reader,&writer,&allowed) | |
| get_devs_in_server(class): | |
| obtains the DevImpl objects instantiated in the same server | |
| get_admin_device: | |
| returns the admin device object itself, not a proxy | |
| get_polled_attrs: | |
| returns the list of internal polled attributes | |
| set_polled_attribute/set_polled_command: | |
| enables polling using the internal admin object | |
| event_received(source,type,value): | |
| event hook | |