processValue
2 minute read
Topic
MQTT: ia/<customerID>/<location>/<AssetID>/processValue
or alternatively: ia/<customerID>/<location>/<AssetID>/processValue/<tagName>
For Kafka just switch the / character with a ..
If you have a lot of processValues, we’d recommend not using the /processValue as topic, but to append the tag name as well, e.g., /processValue/energyConsumption. This will structure it better for usage in MQTT Explorer or for data processing only certain processValues.
For automatic data storage in kafka-to-postgresql both will work fine as long as the payload is correct.
Please be aware that the values may only be int or float, other character are not valid, so make sure there is no quotation marks or anything sneaking in there. Also be cautious of using the JavaScript ToFixed() function, as it is converting a float into a string.
Usage
A message is sent each time a process value has been prepared. The key has a unique name.
Content
| key | data type | description |
|---|---|---|
timestamp_ms | int64 | unix timestamp of message creation |
<valuename> | int64 or float64 | Represents a process value, e.g. temperature |
Pre 0.10.0:
As <valuename> is either of type ´int64´ or ´float64´, you cannot use booleans. Convert to integers as needed; e.g., true = “1”, false = “0”
Post 0.10.0:
<valuename> will be converted, even if it is a boolean value.
Check integer literals and floating-point literals for other valid values.
JSON
Example
At the shown timestamp the custom process value “energyConsumption” had a readout of 123456.
{
"timestamp_ms": 1588879689394,
"energyConsumption": 123456
}
Producers
- Typically Node-RED