Configure Timeout Interpolation

Scenarios

A thermostat temperature sensor reports data only when temperature changes occur. If no data is reported, the temperature is presumed constant. You can use the timeout interpolation node to achieve minute-level data monitoring for such sensors.

Prerequisites

Ensure that data calculation expressions or data filtering filters are set up. For more information, see Configure data computing and data filtering.

Background information

• For an overview of the data parsing feature, see Usage Notes.

• For instructions on using the data parsing workspace, see Data Parsing Workspace Instructions.

Procedure

1. Access the data parsing workbench.

2. In the middle canvas, click the add icon following the current node.

3. In the pop-up node list, single click the Timeout Interpolation node.

4. On the canvas, single click the Timeout Interpolation node. In the configuration panel on the right, set up the timeout interpolation according to the following table:

   Configuration Item	Parameter	Description	Example
   Basic Configuration	Interpolation Time Type	Choose from: Relative Time: Interpolates at regular intervals based on the data parsing task's start time. Set the Relative Time Compensation Period with options such as 10s, 15s, 30s, 1min, 5min, 15min, 30min. Absolute Time: Uses Java (Quartz) standard Crontab expressions to define absolute interpolation times. Set the Absolute Time Compensation Period. For more information, see Appendix: Crontab Expression.	Referencing the "Scenarios" section: For minute-level monitoring, select from two interpolation time types. Relative Time: Choose Relative Time Compensation Period as 1min. Absolute Time: Set the Crontab expression to 0 */1 * * * ?.
   	Interpolation Data Type	Options include: Previous Real Data: Uses the last reported real data for interpolation. Preset Data: Employs predefined data for interpolation. The message content should be in JSON format.	Following the "Scenarios" section: Choose Previous Real Data.
   Advanced Configuration	Message Partition Key	Optional, specifies the dimension for timeout interpolation, often used to distinguish messages from different devices. If not set, the IoT Platform system defaults to using ProductKey and DeviceName as the partition key.	In the "Scenarios" example: Use the thermostat's identity ID, the boxId field, as the partition key.
   	Latency Toleration	Specifies the delay in seconds before interpolating messages to prevent unnecessary interpolation due to real message transmission delays.	Adopt the default settings.
   	Time-to-Live	Defines the maximum duration in seconds to continue interpolation if a topic has not reported messages for an extended period. The minimum purge time is 1 minute, and the maximum is 7 days, with the default being 1 day. The timer resets with each received message.	Maintain the default settings.

   Here is a detailed configuration example based on the "Scenarios" section:

5. To finalize the configuration of the timeout interpolation node, single click Save in the upper right corner of the data parsing workspace.

   Important

   Note: The output fields of this node are identical to those of the preceding node.

What to do next

After you configure the timeout interpolation node, set up additional processing nodes or configure the target node to complete the data parsing task.

Appendix: Crontab Expression

The Java (Quartz) standard Crontab expression is detailed below:

Example:
    # Last day of each month
    @Scheduled(cron = "0 0 18 * * ?")
    public void doAtLastDayOfMonth() {
        // do something here...
    }

    Explanation:
    Java(Quartz)
    *    *    *    *    *    *    *
    -    -    -    -    -    -    -
    |    |    |    |    |    |    |
    |    |    |    |    |    |    + year [optional]
    |    |    |    |    |    +----- day of week (1 - 7) SUN,MON,TUE,WED,THU,FRI,SAT
    |    |    |    |    +---------- month (1 - 12) OR JAN,FEB,MAR,APR ...
    |    |    |    +--------------- day of month (1 - 31)
    |    |    +-------------------- hour (0 - 23)
    |    +------------------------- min (0 - 59)
    +------------------------------ second (0 - 59)