Device publishers write device information to multiple PPS objects in fixed locations. Applications can monitor these objects to learn of device updates and to retrieve information that enables access to device contents.
Publishers can output the following types of PPS object for each device:
| Type | Description | Location |
|---|---|---|
| Device object |
Contains physical and logical connectivity information specific
to the device's hardware type. This information might include:
|
/pps/qnx/device/ |
| Device control object |
Contains commands specifying device actions to perform, such as toggling the power on a port of a USB hub or ejecting a disc. Can also contain command outcomes, depending on the publisher type. Note: The device control objects are PPS server objects. For
information on using server objects, see the Persistent
Publish/Subscribe Developer's Guide.
|
/pps/qnx/device/type_ctrl, where type is either usb or cd0 |
| Driver object | Contains driver information, such as the process name and ID (pid), and a reference to the device object associated with the driver. | /pps/qnx/driver/ |
| Mount object |
Contains information on the device's filesystem, including:
|
/pps/qnx/mount/ |