A Gateway is a program that can be downloaded from Whzan. Its function is to exchange outside world data with Whzan. Gateways can be written to operate on any computer platform as long as it has an internet link.
Taking the X10 home automation Gateway as an example, it can be downloaded from the Whzan Shop and run on a Microsoft Windows PC. Its job is to communicate with the home automation devices in the user's home as well as communicating with Whzan. The Gateway's task is to keep Whzan and the home automation equipment synchronized with each other. For example, if a user switches a local control to turn on a light, the Gateway updates Whzan and any mimics representing the light status will change to match the real world situation. Conversely, if the user clicks on a screen-based switch on the Whzan mimics system via a browser, the Gateway sends the appropriate command to turn on the light at home. Thus Gateways are the bridge between the Whzan system and the real world device or data source.
Gateways supplied by Whzan are free for use and can be found in the shop ready for download. They are easy to install, and on the PC, they operate as a Windows 'service'. They will run as long as the PC is switched on and once installed, they do not require a user to be logged in to operate. When Gateways operate, they synchronize values in the external device with values held in Whzan datapoints. This can be a two-way process.
Whzan Gateways have a second application which is automatically run on setup and can be manually run at any time. This application is the Gateway Manager, its task is to simplify and manage the setup of Whzan and the Gateway. This includes the linking of a device data value such as light on/off to a Whzan datapoint representing the same device value.
Real world devices such as X10 automation controllers or industrial PLCs, have quite complex configurations. The Gateway Manager's job is to simplify the setup process and configure Whzan ready to exchange data. If you add a device to your X10 controller network using the Gateway Manager and call it 'Sprinklers', you will find that the Gateway Manager will create 2 datapoints in Whzan called 'Sprinklers_ActualValue' and 'Sprinklers_RequestedValue'. When the Gateway Service is running, the datapoint 'Sprinklers_ActualValue' will always match the status of the device and the datapoint 'Sprinklers_RequestedValue' will be the status a Whzan user can request. If 'Sprinklers_RequestedValue' changes value in Whzan, the update will be sent to the device via the Gateway Service. After the change, the Gateway Service will read the device status and update 'Sprinklers_ActualValue' accordingly.