don't turn back inverter on unless turned off by BMS

Only allow DVCC to turn an inverter on, if it was previously turned off by
DVCC. If inverter was soft-turned off manually, leave it off.

victronenergy/venus#736

delegates/dvcc.py

@@ -25,6 +25,9 @@
 VEDIRECT_FIRMWARE_REQUIRED = 0x129
 VECAN_FIRMWARE_REQUIRED = 0x10200 # 1.02, 24-bit version
 
+class Flags(object):
+	InverterSwitchedOff = 1 # inverter was switched off when discharge was disabled
+
 # This is a place to account for some BMS quirks where we may have to ignore
 # the BMS value and substitute our own.
 
@@ -244,7 +247,8 @@ def update_values(self):
 
 class Inverter(object):
 	""" Encapsulates an inverter object. """
-	def __init__(self, monitor, service):
+	def __init__(self, dvcc, monitor, service):
+		self.dvcc = dvcc
 		self.monitor = monitor
 		self.service = service
 
@@ -259,17 +263,24 @@ def mode(self, m):
 	def set_maxdischargecurrent(self, limit):
 		""" For plain inverters, a limit of zero turns it off, and a non-zero
 		    limit turns it back on. """
-		m = 2 if limit > 0 else 4 # 2 == invert-only, 4 == off
-		if self.mode != m:
-			self.mode = m
+		if limit == 0 and self.mode != 4:
+			self.dvcc.flags |= Flags.InverterSwitchedOff
+			self.mode = 4 # off
+		elif limit > 0 and self.mode != 2:
+			# If the inverter was turned off by us, switch it back on
+			# This avoids turning the inverter on if it was previously
+			# soft-switched off by something other than DVCC.
+			if self.dvcc.flags & Flags.InverterSwitchedOff:
+				self.dvcc.flags &= ~Flags.InverterSwitchedOff
+				self.mode = 2 # inverter only
 
 class InverterCharger(SolarCharger, Inverter):
 	""" Encapsulates an inverter/charger object, currently the inverter RS,
 	    which has a solar input and can charge the battery like a solar
 	    charger, but is also an inverter.
 	"""
 	def __init__(self, monitor, service):
-		super(InverterCharger, self).__init__(monitor, service)
+		SolarCharger.__init__(self, monitor, service)
 
 	@property
 	def has_externalcontrol_support(self):
@@ -294,7 +305,8 @@ def set_maxdischargecurrent(self, limit):
 
 class InverterSubsystem(object):
 	""" Encapsulate collection of inverters. """
-	def __init__(self, monitor):
+	def __init__(self, dvcc, monitor):
+		self.dvcc = dvcc
 		self.monitor = monitor
 		self._inverters = {}
 
@@ -303,7 +315,7 @@ def _add_inverter(self, ob):
 		return ob
 
 	def add_inverter(self, service):
-		return self._add_inverter(Inverter(self.monitor, service))
+		return self._add_inverter(Inverter(self.dvcc, self.monitor, service))
 
 	def remove_inverter(self, service):
 		del self._inverters[service]
@@ -756,20 +768,22 @@ def get_input(self):
 				'/Link/NetworkMode']),
 			('com.victronenergy.settings', [
 				 '/Settings/CGwacs/OvervoltageFeedIn',
+				 '/Settings/Dvcc/Flags',
 				 '/Settings/Services/Bol'])]
 
 	def get_settings(self):
 		return [
 			('maxchargecurrent', '/Settings/SystemSetup/MaxChargeCurrent', -1, -1, 10000),
 			('maxchargevoltage', '/Settings/SystemSetup/MaxChargeVoltage', 0.0, 0.0, 80.0),
+			('dvcc_flags', '/Settings/Dvcc/Flags', 0, 0, 0),
 			('bol', '/Settings/Services/Bol', 0, 0, 7)
 		]
 
 	def set_sources(self, dbusmonitor, settings, dbusservice):
 		SystemCalcDelegate.set_sources(self, dbusmonitor, settings, dbusservice)
 		self._batterysystem = BatterySubsystem(dbusmonitor)
 		self._solarsystem = SolarChargerSubsystem(dbusmonitor)
-		self._inverters = InverterSubsystem(dbusmonitor)
+		self._inverters = InverterSubsystem(self, dbusmonitor)
 		self._multi = Multi(dbusmonitor, dbusservice)
 
 		self._dbusservice.add_path('/Control/SolarChargeVoltage', value=0)
@@ -848,6 +862,14 @@ def has_dvcc(self):
 		v = self._settings['bol']
 		return bool(v & 1)
 
+	@property
+	def flags(self):
+		return self._settings['dvcc_flags']
+
+	@flags.setter
+	def flags(self, v):
+		self._settings['dvcc_flags'] = int(v)
+
 	@property
 	def bms(self):
 		bmses = sorted(self._batterysystem.bmses,

tests/hub_test.py

@@ -1755,6 +1755,7 @@ def test_inverter_rs_discharge_current(self):
 				'/Link/DischargeCurrent': 0.0}})
 
 	def test_inverter_switchoff_bms(self):
+		from delegates.dvcc import Dvcc
 		# Add inverter
 		self._add_device('com.victronenergy.inverter.ttyO1', {
 			'/Ac/Out/L1/P': 2000,
@@ -1791,9 +1792,58 @@ def test_inverter_switchoff_bms(self):
 		self._check_external_values({
 			'com.victronenergy.inverter.ttyO1': {
 				'/Mode': 4}}) # OFF
+		self.assertTrue(Dvcc.instance.flags & 1) # InverterSwitchedOff flag set
 
 		self._monitor.set_value('com.victronenergy.battery.ttyO2', '/Info/MaxDischargeCurrent', 100.0)
 		self._update_values(interval=3000)
 		self._check_external_values({
 			'com.victronenergy.inverter.ttyO1': {
 				'/Mode': 2}}) # InvertOnly
+
+		self.assertFalse(Dvcc.instance.flags & 1) # InverterSwitchedOff flag unset
+
+	def test_inverter_switchoff_bms2(self):
+		# Leave inverter off and don't turn it back on if it wasn't turned off
+		# by us.
+		# Add inverter
+		self._add_device('com.victronenergy.inverter.ttyO1', {
+			'/Ac/Out/L1/P': 2000,
+			'/Ac/Out/L1/V': 234.2,
+			'/Dc/0/Voltage': 53.1,
+			'/Dc/0/Current': 40.0,
+			'/DeviceInstance': 278,
+			'/Soc': 53.2,
+			'/State': 9,
+			'/Mode': 4, # Off
+			'/IsInverterCharger': 0, # Dumb inverter
+			'/Link/NetworkMode': 0,
+			'/Link/ChargeVoltage': None,
+			'/Link/ChargeCurrent': None,
+			'/Link/DischargeCurrent': None,
+			'/Settings/ChargeCurrentLimit': 100},
+			product_name='Inverter RS', connection='VE.Direct')
+
+		# Battery
+		self._add_device('com.victronenergy.battery.ttyO2',
+			product_name='battery',
+			values={
+				'/Dc/0/Voltage': 53.2,
+				'/Dc/0/Current': 80.0,
+				'/Dc/0/Power': 4000,
+				'/Soc': 43.2,
+				'/DeviceInstance': 512,
+				'/Info/BatteryLowVoltage': 47,
+				'/Info/MaxChargeCurrent': 100,
+				'/Info/MaxChargeVoltage': 58.2,
+				'/Info/MaxDischargeCurrent': 0.0})
+
+		self._update_values(interval=3000)
+		self._check_external_values({
+			'com.victronenergy.inverter.ttyO1': {
+				'/Mode': 4}}) # OFF
+
+		self._monitor.set_value('com.victronenergy.battery.ttyO2', '/Info/MaxDischargeCurrent', 100.0)
+		self._update_values(interval=3000)
+		self._check_external_values({
+			'com.victronenergy.inverter.ttyO1': {
+				'/Mode': 4}}) # Remains OFF