EdgeX Foundry's Command microservice is a conduit for other services to trigger action on devices and sensors through their managing Device Services. See Core Command for more details about this service.
The service provides an API to get the list of commands that can be issued for all devices or a single device. Commands are divided into two groups for each device:
- GET commands are issued to a device or sensor to get a current value for a particular attribute on the device, such as the current temperature provided by a thermostat sensor, or the on/off status of a light.
- SET commands are issued to a device or sensor to change the current state or status of a device or one of its attributes, such as setting the speed in RPMs of a motor, or setting the brightness of a dimmer light.
For EdgeX 2.0 the REST API provided by the Core Command has changed to use DTOs (Data Transfer Objects) for all responses and for all PUT requests. All query APIs (GET) which return multiple objects, such as /all, provide
limit query parameters.