Document Event logging limitations for inverters with battery systems on PV input side.

README.md

@@ -1,6 +1,6 @@
 # OpenDTU logger
 
-OpenDTU logger adds state to OpenDTU and provides detailed, long-term storage and visualisation of Hoymiles solar inverter metrics:
+OpenDTU logger adds detailed, long-term storage and visualisation of Hoymiles solar inverter metrics monitored with OpenDTU:
 
 - It  connects to the OpenDTU livedata websocket and captures metrics.
 - These metrics are inserted into a PostgreSQL database. Optionally, TimescaleDB can be used.
@@ -9,7 +9,17 @@ OpenDTU logger adds state to OpenDTU and provides detailed, long-term storage an
 
 ![PV dashboard in dark mode](https://git.hollander.online/energy/opendtu-logger/raw/commit/a3debb78665641fe7101555d85df89eb0f0d2a79/screenshots/PV-overview-dark-mode.png)
 
-## Install instructions
+## Configuring OpenDTU
+
+In order for OpenDTU Logger to work properly, it is required to ensure the following OpenDTU settings are used.
+
+- Within OpenDTU, go to `Settings` -> `Inverter settings` (<http://YOUR_OPENDTU_IP_ADDRESS/settings/inverter>).
+- For each inverter in the inverter list, click on the pencil (Edit inverter) and go to `Advanced`.
+- Enable `Zero daily yield at midnight` and `Clear Eventlog at midnight`.
+- Click `Save`
+- Repeat this procedure for every inverter.
+
+## OpenDTU logger installation instructions
 
 Docker Compose is the preferred way to install OpenDTU Logger, but using the binary is also possible.
 
@@ -170,8 +180,8 @@ The `grafana` folder contains example dashboards which can be imported into exis
 
 ## Known limitations
 
-- The logger will currently log every event posted by OpenDTU to the websocket. Checks still need to be added to determine the uniqueness of an event. For more information, see also [this OpenDTU Github issue](https://github.com/tbnobody/OpenDTU/issues/1800).
-- Upon restart of the OpenDTU, the OpenDTU Logger binary will need to be restarted as well. When using the provided `compose.yml` files with Docker, or using the `systemd` service file when using the binary, this will happen automatically.
+- The logger currently assumes that events reported by OpenDTU occurred on the current day. This works for the majority of users, as the inverters reset every night when the sun goes down and OpenDTU is configured to forget old events data at midnight. For micro inverters with battery storage added to the PV input side, such as Zendure or Anker Solix, checks still need to be added to account for the fact that these inverters don't necessarily reset every night. Event recording will work, but entries might be recorded multiple times. For more information, see also [this OpenDTU Github issue](https://github.com/tbnobody/OpenDTU/issues/1800).
+- Upon restart of the OpenDTU, the OpenDTU Logger binary needs to be restarted as well. When using the provided `compose.yml` files with Docker, or using the `systemd` service file when using the binary, this happens automatically.
 
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