How to get data with JSON from inverter

General
1

I~m pretty new with programming languages, Nod red and JSON.
I want to get data from a SMA Webbox with "JSON". I already created a couple of nodes (inject node -> change node -> http request node -> debug) has per [Cybertron](https : // How to send a post request with content) post. The "Manufacturer" realesed a guide (http://files.sma.de/dl/2585/SWebBoxRPC-BA-en-14.pdf) where it says that teh request should be in the following form:

RPC={
"version": "1.0",
"proc": "GetPlantOverview",
"id": "1",
"format": "JSON" }

Also the URL for all requests is: http : // IP address/rpcThe IP address in each case is the currently configured IP address of the Sunny WebBox. The default setting is 192.168.0.168.Hence, the default URL is the following: http: // 192.168.0.168/rpcThe request is transmitted via HTTP POST in the body of the HTTP request as a serialized JSON object according to the conventions established in Section 4.1.

Can somebody give me some light? Any clues how to achieve the goals...

Appreciate for some help.

Ricardo

2

Hi Ricardo,

Try this .. we use an inject node .. to triger a function node that sets up a http post request node .. and we get the result in debug.

Screenshot_2020-08-25 Node-RED 192 168 1 160
Screenshot_2020-08-25 Node-RED 192 168 1 160925×157 7.01 KB

[{"id":"5650b8fb.a434","type":"http request","z":"9f2f6aea.6d2be","name":"","method":"use","ret":"obj","paytoqs":"ignore","url":"","tls":"","persist":false,"proxy":"","authType":"","x":630,"y":900,"wires":[["e576fd9b.022f98"]]},{"id":"e576fd9b.022f98","type":"debug","z":"9f2f6aea.6d2be","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":850,"y":900,"wires":[]},{"id":"10c5cdd5.0cf0da","type":"inject","z":"9f2f6aea.6d2be","name":"read","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":"","topic":"","payload":"","payloadType":"date","x":250,"y":900,"wires":[["6cff2930.174fe8"]]},{"id":"6cff2930.174fe8","type":"function","z":"9f2f6aea.6d2be","name":"http post config","func":"\nmsg.headers = {}\nmsg.method = \"POST\"\nmsg.url = \"http://192.168.0.168/rcp\";\nmsg.headers[\"content-type\"] = \"application/json\"\n\nmsg.payload = {\n\"version\": \"1.0\",\n\"proc\": \"GetPlantOverview\",\n\"id\": \"1\",\n\"format\": \"JSON\" }\n\n\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","x":430,"y":900,"wires":[["5650b8fb.a434"]]}]
3

Hi UnborN,

Thanks for the quick reply. Where should try the code, in the inject node? Sorry for my nobby question.

regards,

Ricardo Guita

4

You have to import the flow in Node-red
Details on how to do that can be found here

The inject node is there just to trigger the http request

5

Did the import but some errors poped up

Sunny WebBox




File ExpectationFailed

BuildAndSendResponse
file: temp\wwwroot\
BuildAndSendResponse failed

ERROR

The actual value didn came up

Thanks

6

You imported the flow and then you 'Deploy' ?

If you are just starting Node-red i would recommend going through some really good video tutorials HERE

Can you send us a screenshot of the error ?

7

imagem

Hi UnborN,

Yes I did the Deploy, but it seems that the connection didn´t worked has it should. I alsow changed the IP address of my device (Webbox).

regards,

Ricardo

8

Try replacing the function node code with this :

//msg.headers = {}
msg.method = "POST"
msg.url = "http://192.168.0.168/rcp";
//msg.headers["content-type"] = "application/json"

msg.payload = 'RPC={"version": "1.0","proc": "GetPlantOverview","id": "1","format": "JSON" }'

return msg;
9

Hi,

Here the working code:

[
    {
        "id": "f85209eb.14f638",
        "type": "function",
        "z": "6ca02d32.524864",
        "name": "http post config",
        "func": "\n//msg.headers = {}\nmsg.method = \"POST\"\nmsg.url = \"http://192.168.60.14/rpc\";\n//msg.headers[\"content-type\"] = \"application/json\"\n\nmsg.payload = 'RPC={\"version\": \"1.0\",\"proc\": \"GetPlantOverview\",\"id\": \"1\",\"format\": \"JSON\" }'\n\n\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "x": 380,
        "y": 260,
        "wires": [
            [
                "5c7994b4.af895c"
            ]
        ]
    }
]

[Edited to format correctly]

10

Thanks for your help UnborN.

regards,

11

You are welcome .. so im guessing it worked ?

by the way when you paste code in the forum .. paste it using the < / > icon so it gets formatted correctly. As it is now i cannot import your flow

12

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