I have created two things
1. In first thing(Device) I have written below code in service.
let result = jsonmessage;
2. In second thing(DatabaseController) I want response of Device thing service using below code
var serviceName = "ConvertData";
it is returning blank data.
A service has a return, so in the second service set whatever you want to output as the result and set the output to the proper base type.