Strange output with OPC input and Websockets output

Telegraf
1

Hi,
I am using the OPC input and the Websockets output and the messages look like this:

0: ["host=localhost, id=ns=2;i=6019", "host=localhost, id=ns=2;i=6020",…]
1: [1712615337602, 1712615337602, 1712615337602, 1712615337602, 1712615337602, 1712615337602,…]
2: [0, null, null, null, null, null, null, null, null, null, null, null, null]
3: ["OK (0x0)", "OK (0x0)", "OK (0x0)", "OK (0x0)", "OK (0x0)", "OK (0x0)", "OK (0x0)", "OK (0x0)",…]
4: [null, 0, null, null, null, null, null, null, null, null, null, null, null]
5: [null, null, 0, null, null, null, null, null, null, null, null, null, null]
6: [null, null, null, 0, null, null, null, null, null, null, null, null, null]
7: [null, null, null, null, 0, null, null, null, null, null, null, null, null]
8: [null, null, null, null, null, 46.11357116699219, null, null, null, null, null, null, null]
9: [null, null, null, null, null, null, 44.693050384521484, null, null, null, null, null, null]
10: [null, null, null, null, null, null, null, 1050, null, null, null, null, null]
11: [null, null, null, null, null, null, null, null, 62, null, null, null, null]
12: [null, null, null, null, null, null, null, null, null, 100.44715118408203, null, null, null]
13: [null, null, null, null, null, null, null, null, null, null, 33.551246643066406, null, null]
14: [null, null, null, null, null, null, null, null, null, null, null, 25.07175064086914, null]
15: [null, null, null, null, null, null, null, null, null, null, null, null, 3.363116314379561e-44]

resulting from the following OPC nodes

  nodes = [
   {name="Latitude", namespace="2", identifier_type="i", identifier="6019"},
   {name="Longitude", namespace="2", identifier_type="i", identifier="6020"},
   {name="EPY", namespace="2", identifier_type="i", identifier="6021"},
   {name="EPX", namespace="2", identifier_type="i", identifier="6022"},
...

So for each of the latter entries has only one non-null entry for the respective node ID as given in the first row. However, I would actually expect that there is either only one row with all the values or just one value in each row. Why is there this full matrix?

Thanks,
Florian

2

I’m not familiar with the websocket output of Telegraf, but this behavior might be related to the OPC UA input plugin emitting a metric for every node configured. What do you see if you use the file output or run telegraf with --test?

Aggregating the metrics into a single metric is supported natively with the telegraf/plugins/aggregators/merge at master · influxdata/telegraf · GitHub plugin.

1 Like
3

@Florian_Kauer your output looks like the metrics are “interlaced” with the first list contains the tags, the second one the timestamps, then fields etc. Please add a file output like

[[outputs.file]]
  files = ["stdout"]

to see the actual metrics in the console (or replace stdout by an actual file-path to store the metrics in a file). Post a (redacted) subset of the resulting metrics here and also show an example for how the websocket output should look like!