diff --git a/RCUSCC/RCUSCC/RCUSCC.py b/RCUSCC/RCUSCC/RCUSCC.py
index 30bd2aabe9c0feeb0200ce907af1640e25062438..eec910de17bde6678de7e4a6dbef8da558f405de 100644
--- a/RCUSCC/RCUSCC/RCUSCC.py
+++ b/RCUSCC/RCUSCC/RCUSCC.py
@@ -25,7 +25,7 @@ import sys
import opcua
import numpy
-from wrappers import only_when_on, fault_on_error
+from wrappers import only_in_states, only_when_on, fault_on_error
from opcua_connection import OPCUAConnection
__all__ = ["RCUSCC", "main"]
@@ -42,6 +42,25 @@ class RCUSCC(Device):
- Type:'DevULong'
OPC_Time_Out
- Type:'DevDouble'
+
+ States are as follows:
+ INIT = Device is initialising.
+ STANDBY = Device is initialised, but pends external configuration and an explicit turning on,
+ ON = Device is fully configured, functional, controls the hardware, and is possibly actively running,
+ FAULT = Device detected an unrecoverable error, and is thus malfunctional,
+ OFF = Device is turned off, drops connection to the hardware,
+
+ The following state transitions are implemented:
+ boot -> OFF: Triggered by tango. Device will be instantiated,
+ OFF -> INIT: Triggered by device. Device will initialise (connect to hardware, other devices),
+ INIT -> STANDBY: Triggered by device. Device is initialised, and is ready for additional configuration by the user,
+ STANDBY -> ON: Triggered by user. Device reports to be functional,
+ * -> FAULT: Triggered by device. Device has degraded to malfunctional, for example because the connection to the hardware is lost,
+ * -> FAULT: Triggered by user. Emulate a forced malfunction for integration testing purposes,
+ * -> OFF: Triggered by user. Device is turned off. Triggered by the Off() command,
+ FAULT -> INIT: Triggered by user. Device is reinitialised to recover from an error,
+
+ The user triggers their transitions by the commands reflecting the target state (Init(), On(), Fault()).
"""
client = 0
name_space_index = 0
@@ -207,11 +226,16 @@ class RCUSCC(Device):
self.debug_stream("Mapping OPC-UA MP/CP to attributes done.")
def init_device(self):
- """Initialises the attributes and properties of the RCUSCC."""
+ """ Instantiates the device in the OFF state. """
# NOTE: Will delete_device first, if necessary
Device.init_device(self)
+ self.set_state(DevState.OFF)
+
+ def initialise(self):
+ """Initialises the attributes and properties of the RCUSCC."""
+
self.set_state(DevState.INIT)
# Init the dict that contains attribute to OPC-UA MP/CP mappings.
@@ -257,9 +281,10 @@ class RCUSCC(Device):
self.client = opcua.Client("opc.tcp://{}:{}/".format(self.OPC_Server_Name, self.OPC_Server_Port), self.OPC_Time_Out) # timeout in seconds
- # Connect to OPC-UA -- will set ON state on success
- self.opcua_connection = OPCUAConnection(self.client, self.On, self.Fault, self)
+ # Connect to OPC-UA -- will set ON state on success in case of a reconnect
+ self.opcua_connection = OPCUAConnection(self.client, self.Standby, self.Fault, self)
+ # Explicitly connect
if not self.opcua_connection.connect():
# hardware or infra is down -- needs fixing first
self.Fault()
@@ -276,16 +301,8 @@ class RCUSCC(Device):
# Start keep-alive
self.opcua_connection.start()
- # Everything went ok -- go online
- self.On()
-
- @DebugIt()
- def On(self):
- """
-
- :return:None
- """
- self.set_state(DevState.ON)
+ # Everything went ok -- go standby.
+ self.set_state(DevState.STANDBY)
def always_executed_hook(self):
@@ -432,23 +449,53 @@ class RCUSCC(Device):
@command(
)
+ @only_in_states([DevState.FAULT, DevState.OFF])
@DebugIt()
def Init(self):
"""
+ Command to ask for initialisation of this device. Can only be called in FAULT or OFF state.
+
+ :return:None
+ """
+
+ self.initialise()
+
+ @only_in_states([DevState.INIT])
+ def Standby(self):
+ """
+ Command to ask for initialisation of this device. Can only be called in FAULT or OFF state.
:return:None
"""
- self.init_device()
+ self.set_state(DevState.STANDBY)
+
+ @command(
+ )
+ @only_in_states([DevState.STANDBY])
+ @DebugIt()
+ def On(self):
+ """
+ Command to ask for initialisation of this device. Can only be called in FAULT or OFF state.
+
+ :return:None
+ """
+
+ self.set_state(DevState.ON)
@command(
)
@DebugIt()
def Off(self):
"""
+ Command to ask for shutdown of this device.
:return:None
"""
+ if self.get_state() == DevState.OFF:
+ # Already off. Don't complain.
+ return
+
# Turn off
self.set_state(DevState.OFF)
@@ -458,15 +505,17 @@ class RCUSCC(Device):
# Turn off again, in case of race conditions through reconnecting
self.set_state(DevState.OFF)
-
@command(
)
+ @only_in_states([DevState.ON, DevState.INIT, DevState.STANDBY])
@DebugIt()
def Fault(self):
"""
FAULT state is used to indicate our connection with the OPC-UA server is down.
- This device will try to reconnect, and transition to the ON state on success.
+ This device will try to reconnect once, and transition to the ON state on success.
+
+ If reconnecting fails, the user needs to call Init() to retry to restart this device.
:return:None
"""
diff --git a/RCUSCC/RCUSCC/wrappers.py b/RCUSCC/RCUSCC/wrappers.py
index 964fa46986edbd8eb8f1876deb8fe5c7c36bde56..dfd4fe3f444c0cbb572e53f7b0386b2882171e55 100644
--- a/RCUSCC/RCUSCC/wrappers.py
+++ b/RCUSCC/RCUSCC/wrappers.py
@@ -2,7 +2,23 @@ from tango import DevState
from functools import wraps
import traceback
-__all__ = ["only_when_on", "fault_on_error"]
+__all__ = ["only_in_states", "only_when_on", "fault_on_error"]
+
+def only_in_states(func, allowed_states):
+ """
+ Wrapper to return None when the device isn't in ON state.
+
+ If in ON state, calls & returns the wrapped function.
+ """
+
+ @wraps(func)
+ def state_check_wrapper(self, *args, **kwargs):
+ if self.get_state() not in allowed_states:
+ return None
+
+ return func(self, *args, **kwargs)
+
+ return state_check_wrapper
def only_when_on(func):
"""