How to read current and temperature

Question

How to read current and temperature

Closed this issue 6 months ago · 6 comments

Hello, I would like to know how to collect current and temperature data, and how to display them on the transaction list. Which files do I need to modify?

Answer 1 · 2023-12-27T14:04:30.000Z

It all depends on what the charger sends. You can look at the schema of the MeterValues-Reqest to see what measured values are technically possible:
https://github.com/dallmann-consulting/OCPP.Core/blob/main/OCPP.Core.Server/Schema16/MeterValuesRequest.json

And here is sample MeterValueRequest from our real life chargers:

[2,"eb07f294-f7b3-4a70-b2fe-a1ad375236ba","MeterValues",{"connectorId":4,"transactionId":14,"meterValue":[{"timestamp":"2021-04-08T17:40:33.000Z","sampledValue":[{"value":"164.5","context":"Sample.Periodic","format":"Raw","measurand":"Energy.Active.Import.Register","location":"Outlet","unit":"Wh"}]}]}]

You can see that there is no current, temperature and not even a SoC. Just an updated meter value in Wh.

Answer 2 · 2024-01-05T14:55:23.000Z

Where can I see these things?"[2,"eb07f294-f7b3-4a70-b2fe-a1ad375236ba","MeterValues",{"connectorId":4,"transactionId":14,"meterValue":[{"timestamp":"2021-04-08T17:40:33.000Z","sampledValue":[{"value":"164.5","context":"Sample.Periodic","format":"Raw","measurand":"Energy.Active.Import.Register","location":"Outlet","unit":"Wh"}]}]}]"

Answer 3 · 2024-01-05T16:11:13.000Z

You can read the OCPP specification for that. But it might help to just format the message:

[2,"eb07f294-f7b3-4a70-b2fe-a1ad375236ba","MeterValues",
{
  "connectorId":4,
  "transactionId":14,
  "meterValue":[{"timestamp":"2021-04-08T17:40:33.000Z",
                 "sampledValue":[{"value":"164.5",
				"context":"Sample.Periodic",
				"format":"Raw",
				"measurand":"Energy.Active.Import.Register",
				"location":"Outlet",
				"unit":"Wh"}]}]
}]

The two most significant values are:
"value":"164.5"
"unit":"Wh"
So the charger sends a new meter value of 164,5 Wh (the charger was brand new...). OCPP also allows other values (e.g. SoC) but our charger doesn't send anything.

Answer 4 · 2024-01-22T15:15:33.000Z

Hello, what program should I run to see the following message? =>[2,"eb07f294-f7b3-4a70-b2fe-a1ad375236ba","MeterValues",
{
"connectorId":4,
"transactionId":14,
"meterValue":[{"timestamp":"2021-04-08T17:40:33.000Z",
"sampledValue":[{"value":"164.5",
"context":"Sample.Periodic",
"format":"Raw",
"measurand":"Energy.Active.Import.Register",
"location":"Outlet",
"unit":"Wh"}]}]
}]

Answer 5 · 2024-01-22T17:41:23.000Z

This is the raw OCPP message the charger sends to the OCPP backend. I don't think there is a program to "see" this. It is basically readable text in a technical JSON format.

Answer 6 · 2024-03-04T17:11:07.000Z

You can read the OCPP specification for that. But it might help to just format the message:
[2,"eb07f294-f7b3-4a70-b2fe-a1ad375236ba","MeterValues",
{
  "connectorId":4,
  "transactionId":14,
  "meterValue":[{"timestamp":"2021-04-08T17:40:33.000Z",
                 "sampledValue":[{"value":"164.5",
				"context":"Sample.Periodic",
				"format":"Raw",
				"measurand":"Energy.Active.Import.Register",
				"location":"Outlet",
				"unit":"Wh"}]}]
}]
The two most significant values are: "value":"164.5" "unit":"Wh" So the charger sends a new meter value of 164,5 Wh (the charger was brand new...). OCPP also allows other values (e.g. SoC) but our charger doesn't send anything.

Type2 doesn't transfer SoC to the charging station per definition. So the wallbox can't transfer it to the OCPP server.
I think SoC is added for DC wallboxes with CCS plugs.