You can use the data forwarding feature of the rules engine to forward data to Function Compute. Then, Function Compute uses function scripts to process business data.This article describes the data forwarding process. In this example, a Thing Specification Language (TSL) communication topic is used as the source topic.

Prerequisites

  • A data source named DataSource is created and a TSL communication topic is added the data source. For more information, see Create a data source.
  • A Function Compute service and a function are created. The function is configured and can run as expected after verification. For more information, see the Function Compute documentation.
    Notice If you use an IoT Platform instance of the Enterprise Edition, the region where the Function Compute service resides must be the same as that of the IoT Platform instance.

Background information

The rules engine uses the data forwarding feature to forward device data to Function Compute. Then, Function Compute runs business-specific function scripts to implement various business features.

The following figure shows the data forwarding procedure.

Forward data to Function Compute

Create a data destination

  1. Log on to the IoT Platform console.
  2. On the Overview page, find the instance and click the instance name to go to the Instance Details page.
    Notice Enterprise Edition instances are available only in the Japan (Tokyo) region. If your IoT Platform is not activated in the Japan (Tokyo) region, skip this step.
    Overview
  3. In the left-side navigation pane, choose Rules Engine > Data Forwarding.
  4. Optional:On the Data Forwarding page, click Go to New Version in the upper-right corner to go to the new version.
    Note If you have performed this step, the Data Forwarding page of the new version appears after you choose Rules > Data Forwarding.
  5. Click the Data Destination tab. On this tab, click Create Data Destination.
  6. In the Create Data Destination dialog box, enter a data destination name. In this example, enter DataPurpose. Set the parameters and then click OK.
    Parameter Description
    Operation Select Send Data to Function Compute.
    Region Select a region where your Function Compute service is deployed.
    Services Select a Function Compute service.

    You can click Create Service to go to the Function Compute console and create a service. For more information, see the Function Compute documentation.

    Function Select a function that is used to receive data.

    You can click Create Function to go to the Function Compute console and create a function.

    Authorization Grant IoT Platform the permissions to write data to Function Compute.

    If you have not created a Resource Access Management (RAM) role, click Create RAM Role to go to the RAM console, create a RAM role, and then grant permissions. For more information, see Create a RAM role.

Configure and start a parser

  1. Create a parser named DataParser. For more information, see Create a parser.
  2. On the Parser Details page, associate the parser with the created data source.
    1. In the Data Source step of the wizard, click Associate Data Source.
    2. In the dialog box that appears, select DataSource from the Data Source drop-down list, and then click OK.
  3. On the Parser Details page, associate the parser with the created data destination.
    1. Click Data Destination in the wizard. In the Data Destination section, click Associate Data Destination.
    2. In the dialog box that appears, select DataPurpose from the Data Destination drop-down list, and then click OK.
    3. In the Data Destination section, view and save the data destination ID. In this example, the ID is 1000.
      When you write the parser script, you must use the data destination ID.
  4. On the Parser Details page, click Parser.
  5. In the code editor, enter a script. For more information about how to write a script, see Sample script.
    For more information about the function parameters, see Functions.
    // Use the payload() function to obtain the data that is submitted by devices and convert the data by using the JSON format. 
var data = payload("json");
// Forward submitted TSL data. 
writeFc(1000, data)
  6. Click Debugging. In the dialog box that appears, select a product and a device, specify a topic, and enter payload data to verify whether the script can run properly.
    The following figure shows the parameters.Debugging example

    The following result indicates that the script is implemented.

    Debugging result
  7. Click Publish.
  8. Go to the Parser tab of the Data Forwarding page. Find the DataParser parser and click Start in the Actions column to start the parser.
  9. Log on to the Function Compute console. On the Log Query tab of the Function Details page, view the running records of the function. Click Real-time Monitoring in the upper-right corner to view the monitoring statistics on the function.
    Notice The monitoring statistics on a function are generated 5 minutes after the function runs.