Mapping IzoT Device Datapoints to IzoT Server Datapoints Overview

Owned by Sacha Parisot (Unlicensed)
06-Jun-2022
2 min read

The IzoT Server enables Web pages and enterprise applications to interact with devices on an IzoT network, and their datapoints. An IzoT device application may implement up to 4096 datapoints, and each of the datapoints may be a simple scalar value, or may be a structure of up to 228 bytes consisting of multiple fields. The IzoT Server exposes datapoints as scalar or enumeration values. Files called device class files are used to define the mapping of the datapoints and datapoint fields implemented by an IzoT device application and the datapoints exposed by the IzoT Server.

The specification of the datapoints implemented by an IzoT device application is called the IzoT device interface. The IzoT device interface is uniquely identified by a program ID. Each device class file includes a program ID that associates the device class file with an IzoT device application. When the IzoT Server discovers a new device, the server reads the program ID from the new device and then searches for a matching device class file in the etc/lonbridge/classes directory. If the IzoT Server finds a device class file with a matching program ID, the IzoT Server stores information about the discovered device in the devices.xml file in the etc/lonbridge/ instances directory.

Multiple example device class files are included with the IzoT SDK. The following table lists the device class files for the IzoT SDK example applications.

Class FileApplicationProgram ID
env_sensor.xmlEnvironment Sensor9F:FF:FF:05:00:68:00:03
keypad.xmlKeypad9F:FF:FF:05:00:70:00:01
led_controller.xmlLED Controller9F:FF:FF:05:00:6F:00:02
multi_dio_1_channel.xmlMulti DIO 1-Channel9F:FF:FF:05:00:51:00:11
multi_dio_2_channels.xmlMulti DIO 2-Channel9F:FF:FF:05:00:51:00:12
multi_dio_3_channels.xmlMulti DIO 3-Channel9F:FF:FF:05:00:51:00:13
multi_dio_4_channels.xmlMulti DIO 4-Channel9F:FF:FF:05:00:51:00:14
multi_dio_5_channels.xmlMulti DIO 5-Channel9F:FF:FF:05:00:51:00:15
multi_dio_6_channels.xmlMulti DIO 6-Channel9F:FF:FF:05:00:51:00:16
multi_dio_7_channels.xmlMulti DIO 7-Channel9F:FF:FF:05:00:51:00:17

To add a new device for the IzoT Server to monitor or control, add an XML file for the device to the classes directory. 

To modify which IzoT device datapoints the IzoT Server monitors or controls for a device, edit the appropriate device class file with any text editor.

You must stop and restart the IzoT Server whenever you add or change a device class file.

The following topics provide additional information on device class files: