Session time and other measurands are not reported when stop transaction is executed in Etrel Inch

[mazzy89]

Version of the custom_component

v0.5.0

Configuration

Add your logs here.

Describe the bug

I charge my EV that it is set to 80% charging limit. Once it gets to 80% it stops charging. The CS responds that EV stopped charging. The charging session is then paused until I go to my charging station and click stop session.
At that point this logic is executed

ocpp/custom_components/ocpp/api.py

Line 1381 in 5ad31b4

def on_stop_transaction(self, meter_stop, timestamp, transaction_id, **kwargs):

It is not clear to me why in that logic the session time is not registered. We should also report the session time when the session is stopped.

Debug log

Add your logs here.

[mazzy89]

I've found out that the session time is registered here

ocpp/custom_components/ocpp/api.py

Line 1100 in 5ad31b4

def on_meter_values(self, connector_id: int, meter_value: dict, **kwargs):

when meter values are sent. However I have found out the warning message

2023-12-07 12:00:00.152 WARNING (MainThread) [custom_components.ocpp] Unknown transaction detected with id=-16

and since there is no transaction_matches set to True the session time is never registered.

ocpp/custom_components/ocpp/api.py

Line 1131 in 5ad31b4

if transaction_id == self.active_transaction_id and transaction_id != 0:

The transaction_id is set to -16 while the value in the sensor.charger_transaction_id (which I assume is self.active_transaction_id is 1701939251 which create a mismatch.

[mazzy89]

self.active_transaction_id

is set at the start of the charging with the time in unix format.

but then the transaction ID is retrieved from the context here

ocpp/custom_components/ocpp/api.py

Line 1103 in 5ad31b4

transaction_id: int = kwargs.get(om.transaction_id.name, 0)

so there is a mismatch of the values.

Pinging here @lbbrhzn since you have introduced transaction_id in the unix format in this PR.
https://github.com/lbbrhzn/ocpp/pull/437/files

could you explain why you have used unix time?

[mazzy89]

It would be nice to get here an answer so to wire changes to add support for Etrel stations.

[mazzy89]

I've also noticed that when the charging session terminates because the car is charged, differently by the case when the session is stopped manually, no measured is reported. At this stage it makes this integration not suitable for Etrel charging station unless we fix this problem and make happen the transaction matches.

[mazzy89]

I guess the missing logic resides somewhere in between these lines

ocpp/custom_components/ocpp/api.py

Lines 1117 to 1127 in 5ad31b4

	if self._metrics[csess.transaction_id.value].value is None:
	value = self.get_ha_metric(csess.transaction_id.value)
	if value is None:
	value = kwargs.get(om.transaction_id.name)
	else:
	value = int(value)
	_LOGGER.debug(
	f"{csess.transaction_id.value} was None, restored value={value} from HA."
	)
	self._metrics[csess.transaction_id.value].value = value
	self.active_transaction_id = value

I have added some debug output and in the next charge session I'm going to print out values of transaction_id and active_transaction_id

Ideally I would like to wire out a PR to cover these two missing things:

• Add session time in on_stop_transaction function
• Fix logic to match transaction id and allow measured to be reported

I will continue and report updates later once I will have charged the car and get some meaningfull logs

[mazzy89]

I can confirm that no meter values are written because the transaction mismatch.

active_transaction_id is an unix time while my transaction id is a counter of the charging sessions in my station. Then there is always a mismatch and no data is propagate from the station to HA. Not sure though my transaction id is a negative number but i do not think it is a big deal

2023-12-12 11:55:02.776 INFO (MainThread) [ocpp] charger: receive message [2,"af","MeterValues",{"connectorId":1,"meterValue":[{"timestamp":"2023-12-12T10:54:59.669Z","sampledValue":[{"value":"15.44","context":"Sample.Clock","measurand":"Current.Import","phase":"L1","unit":"A"},{"value":"14.944","context":"Sample.Clock","measurand":"Current.Import","phase":"L2","unit":"A"},{"value":"15.2","context":"Sample.Clock","measurand":"Current.Import","phase":"L3","unit":"A"},{"value":"40.290667","context":"Sample.Clock","measurand":"Energy.Active.Import.Register","unit":"kWh"},{"value":"50.01","context":"Sample.Clock","measurand":"Frequency"},{"value":"3.584","context":"Sample.Clock","measurand":"Power.Active.Import","phase":"L1","unit":"kW"},{"value":"3.456","context":"Sample.Clock","measurand":"Power.Active.Import","phase":"L2","unit":"kW"},{"value":"3.504","context":"Sample.Clock","measurand":"Power.Active.Import","phase":"L3","unit":"kW"},{"value":"10.56","context":"Sample.Clock","measurand":"Power.Active.Import","unit":"kW"},{"value":"0.975","context":"Sample.Clock","measurand":"Power.Factor"},{"value":"13","context":"Sample.Clock","measurand":"Temperature","unit":"Celsius"},{"value":"239.06","context":"Sample.Clock","measurand":"Voltage","phase":"L1","unit":"V"},{"value":"236.83","context":"Sample.Clock","measurand":"Voltage","phase":"L2","unit":"V"},{"value":"236.63","context":"Sample.Clock","measurand":"Voltage","phase":"L3","unit":"V"}]}],"transactionId":-27}]

I've looked at the logic and active_transaction_id is used to calculate the session time. So if I set it to my transaction_id it will break the session duration sensor.

I can't change the transaction_id coming from my charging station. then the only way to approach this would be to change it in backend here.

[mazzy89]

In the StartTransaction I do not have any transaction_id so in the function on_start_transaction I cannot pull any other transaction_id to replace the current one with the unix time.

[mazzy89]

I've noticed that the integration sets the transaction id as Unix time and then it sends it to the charging station. Is the charging station supposed to set this transaction id? Does it belong to the OCPP standard? Because in that case, it is an issue with my charging station that does not set tback the transaction id

[lbbrhzn]

accordiing to the OCPP standard the Central System specifies the transaction ID. For this integration we chose to derive the transaction from the unix time, because it guarantees a unique transaction id for every transaction, and allows you to easily derive the session time, even when home assistant is rebooted. If we would use some other scheme, we would need to be able to store the transaction id and the session starting time for each transaction persistently.

[mazzy89]

@lbbrhzn So then at this point is my charging station vendor that is not following the OCPP standard? what do you recommend then? any ideas?
I can get back to the vendor and ask for more information. otherwise any other ideas on how to accommodate this use case? I'm keen to hear and have the bandwidth and skills to implement any required changes on this integration.

[lbbrhzn]

This is the OCPP standard:

The transaction ID is generated by the Central System, and reported back by the charger. If your vendor is doing something else, your best option is to ask them to comply to the standard.

[mazzy89]

ok then it's my station and the vendor that does not follow the standard or some issues in their software. I will ask to the vendor.

[lbbrhzn]

If your charger is not compliant, you may be able to work around it (by storing the time of the start transaction locally), but I would urge you to fork the project and do your modifications there. In general we don't include fixes for non-compliant chargers in this repository, because of the risk breaking things for chargers that are fully compliant.

[mazzy89]

Thanks for the recommendation @lbbrhzn and yes it makes perfect sense to not include workarounds here for non-complaint charging stations.

I'm writing to the vendor's support and finding out what they say.

Meanwhile, I might overcome this issue by calculating the session time by looking at the status of the connector. I should be able to do that.