www.advantech.com/products Online Download Data Acquisition and Sensing in IoT IoT Architecture There are two different ways to get the devices to the cloud. For legacy devices, an IoT gateway can be used to perform protocol translation and data aggregation. A gateway then publishes the aggregated data to the cloud. For IoT devices which support Ethernet, it can be directly connected to the cloud to provide further service if there are not many devices in the system, or the devices are widely deployed in different areas. Otherwise, an IoT gateway can be used to manage the data before publishing to the cloud to reduce the connections between cloud and devices, or reducing the network bandwidth. RESTful API Representational State Transfer (REST) is a software architecture style and widely used for creating scalable web services. With the advantage of scalability, simplicity and performance, it's already adopted in IoT applications. It is based on Hypertext Transfer Protocol (HTTP) and uses verbs, like GET, POST, PUT, DELETE, etc., for web browsers to get web pages or retrieve data with remote servers. The data can be retrieved by internet media like HTML, XML, or JSON. REST is a Uniform Resource Identifier (URI) used to identify data, like using “” to identify the analog input value of channel 0, so the web server may retrieve a JSON file analog input value of channel 0. Secure Socket Compared to Modbus/TCP which is also based on TCP, RESTful API provides higher scales to be used in wide area network (WAN). Modbus/TCP does not support security, so it can only be used in local area networks (LAN). However, RESTful which uses HTTP for data retrieval, can support HTTPS (HTTP over SSL (Secure Socket Layer)) or TLS (Transport Layer Secure). For developing IoT applications, RESTful API will be a better option for publishing data to the cloud or retrieving data between devices. Automation Protocol RESTful Web API IoT Wireless I/O Modules Overview Power & Energy Automation 8 5 4 4 10 Panel PCs 9 iDoor Technology Modules 8 Industrial monitors 7 Industrial IoT Gateways 6 Control Cabinet PCs High-Performance Control Panels Industrial Operator Panels 3 2 IntelligentMotionControl andMachineVision 1 11 Control IPCs 12 Remote DA&C Systems 13 Wireless IoT Sensing Devices 14 15 RS-485 I/O Modules 16 Thin-Client Terminals Industrial Ethernet Solutions 17 IP Gateway and Serial Device Servers iNetworking 18 19 WebAccess+ Solution Ethernet I/O Modules Chapter 14 Table of Contents Table of Contents