Unit 4: Controlling Device State¶

After the battery device is connected into the EnOS Cloud, you can send commands to control the device state with the defined service. In this tutorial, use the start_charging service defined in the battery model to control the charging state of the battery device. Detailed steps are as follows:

Define the start_charging service for the battery model. See the following example:

The details of the input parameter are as follows:
- Parameter Name: result
- Identifier: result
- Data Type: int
With the start_charging service, you can send instructions from the cloud to the battery device. For more information on how to define a feature of a model, see Creating Model.

Declare the following main functions for simulating device data:

public static void main(String[] args) throws Exception {
    initWithCallback();
    handleServiceInvocation();
}

Use the handleServiceInvocation function to process the service invocation:

public static void handleServiceInvocation() {
        IMessageHandler<ServiceInvocationCommand, ServiceInvocationReply> handler = new IMessageHandler<ServiceInvocationCommand, ServiceInvocationReply>() {
            public ServiceInvocationReply onMessage(ServiceInvocationCommand request, List<String> argList) throws Exception {
                System.out.println("rcvn async service invocation command" + request + " topic " + argList);
                return (ServiceInvocationReply)ServiceInvocationReply.builder().addOutputData("point1", 11).build();
            }
        };
        client.setArrivedMsgHandler(ServiceInvocationCommand.class, handler);
    }

Run your Java code.
Use the debugging function in Asset Management > Product > Product Details > Debugging to test sending instructions to the device.
Select the start_charging service from the Debugging field, input a value for the result parameter, and click Run. The instruction will be sent to the device.

The running program will receive the service invocation message. See the following example:

rcvn async service invocation commandAnswerableMessageBody{id='2267850613537742848', method='thing.service.start_charging', version='1.0', params={result=1}} topic [OjupXK76, keyofbattery1, start_charging]

Next Unit¶

Monitoring the Device Performance with Alerts