Introduce STANDBY state, representing an initialised device that still can be...

Introduce STANDBY state, representing an initialised device that still can be configured and put explicitly online (ON)

RCUSCC/RCUSCC/RCUSCC.py

@@ -44,21 +44,23 @@ class RCUSCC(Device):
             - Type:'DevDouble'
 
     States are as follows:
-        ON = Device is functional and controls the hardware,
-        OFF = Device is turned off, drops connection to the hardware,
-        FAULT = Device detected an unrecoverable error, and is malfunctional,
         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 -> INIT:  Device will initialise when it is started,
-        INIT -> ON:    Device will report to be functional when initialisation succeeds
-        INIT -> FAULT: Device will degrade to malfunctional if initialisation fails
-        ON -> FAULT:   Device will degrade to malfunctional if an unrecoverable error is encountered
-        * -> OFF:      Device is turned off. Triggered by the Off() command.
-        FAULT -> INIT: Device is reinitialised to recover from an error. Triggered by the Init() command.
-        OFF -> INIT:   Device is turned on again. Triggered by the Init() command.
-
-    For integration testing reasons, the user is allowed to manually set the device to FAULT.
+        boot -> INIT:    Triggered by device. Device will initialise when it is started,
+        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,
+        OFF -> INIT:     Triggered by user.   Device is turned on again.
+
+        The user triggers their transitions by the commands reflecting the target state (Init(), On(), Fault()).
     """
     client = 0
     name_space_index = 0
@@ -274,9 +276,10 @@ 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()
@@ -293,8 +296,8 @@ class RCUSCC(Device):
         # Start keep-alive
         self.opcua_connection.start()
 
-        # Everything went ok -- go online
-        self.set_state(DevState.ON)
+        # Everything went ok -- go standby.
+        self.set_state(DevState.STANDBY)
 
 
     def always_executed_hook(self):
@@ -452,6 +455,29 @@ class RCUSCC(Device):
 
         self.init_device()
 
+    @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.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()
@@ -476,7 +502,7 @@ class RCUSCC(Device):
 
     @command(
     )
-    @only_in_states([DevState.ON, DevState.INIT])
+    @only_in_states([DevState.ON, DevState.INIT, DevState.STANDBY])
     @DebugIt()
     def Fault(self):
         """