Device Service Component Configuration

The following table describes the configuration variables that can be used with all Device Service components:

Parameter	Type	Description	Valid Values	Required
Library	String	The shared library implementing the Device Service component	libxrt-{protocol}-device-service.so	Y - When using dynamic linking
Factory	String	The name of the C function used to instantiate the component	xrt_{protocol}_device_service_factory	Y - When using dynamic linking
Name	String	The name of the Device Service		Y
TelemetryTopic	String	The name of the topic on which to publish data from a service including scheduled events, COVs and more		Y
NotificationTopic	String	The name of the topic on which to publish notifications from connected devices		N
RequestTopic	String	The name of the topic on which to receive requests from the Bus		Y
ReplyTopic	String	The name of the topic on which to publish request replies to the Bus		Y
DiscoveryTopic	String	The name of the topic on which to publish discovery requests to the Bus		N
StatusTopic	String	The name of the topic on which to publish change of operational state events to the Bus		N
RequestQueueMax	Unsigned Integer	The maximum size of the queue for requests	Default: 4	N
DiscoveryInterval	Unsigned Integer	The interval in seconds in which discovery will be triggered	Default: 0	N
ScheduleDeadBand	Unsigned Integer	A schedules initial start time can be anytime within its interval. This option can reduce the range of the start time by setting a dead band at the end of the potential start time in milliseconds. For example, a schedule with an interval of 10 seconds, a dead band of 2000 ms would mean the initial start time of the schedule would occur within 0 to 8 seconds instead of 0 to 10	Default: 0	N
Timestamp	Boolean	Include timestamp in reading	Default: false	N
AutoRegister	Boolean	Automatically add discovered devices	Default: false	N
PublishRegisteredDevices	Boolean	On starting Xrt, details of the devices already registered will be published	Default: false	N
PublishAttributes	Boolean	Include attributes in reading	Default: false	N
SchedulesThreadPool	String	Assign a dedicated Threadpool component for Schedules to use. By default all Schedule events will run in the common Threadpool	A string with the name of the ThreadPool component to use	N
RequestsThreadPool	String	Assign a dedicated Threadpool component for explicit put/get operations. By default all put/get operations will run in the common Threadpool	A string with the name of the ThreadPool component to use	N
SyncPostData	Boolean	Set whether to publish messages synchronously (true) or asynchronously (false)	Default: false	N
EdgeXCompat	Boolean	Determines whether returned readings should be EdgeX compatible	Default: false	N
ZeroNullReadings	Boolean	If a device service returns a null reading, then the value will be converted to a zeroed value of the readings type	Default: false	N
DiscardUnchangedReadings	Boolean	If the on_change option is set on a schedule for multiple resources, only those resources which have changed values will be published. Set this option to false to cause all resources in a schedule to be published whenever one or more of them has changed	Default: true	N
EnableDiscovery	Boolean	Enable discovery for the service	Default: false	N
PreloadCache	Boolean	Specify true to load resource metadata cache with device profiles on initialization Specify false to cache resource metadata on demand Provides the optimal response time for the first request for a specified resource at the cost of increased memory use and start-up time	Default: false	N
ProfileDir	String	The full path of the directory containing the device profiles and ProfileListFile		Y
ProfileListFile	String	The name of the JSON file that contains the list of device profiles to load The file list is represented as an array of strings This JSON file and the entries in the array are relative to the path defined in ProfileDir and have a .json extension If not present, a profiles.json file in the path defined in ProfileDir is read to provide the profile files to load A JSON file that matches the name of the JSON file specified in this parameter must be present in the path defined in ProfileDir	Default: profiles	N
DevicesFile	String	The name of the JSON file that contains the list of devices to load The file list is represented as an array of device objects This JSON file and the entries in the array are relative to the path defined in StateDir and have a .json extension If not present, a devices.json file in the path defined in StateDir is read to provide the devices to load A JSON file that matches the name of the JSON file specified in this parameter must be present in the path defined in StateDir	Default: devices	N
SchedulesFile	String	The name of the JSON file that contains the list of schedules to load The file list is represented as an array of schedule objects This JSON file and the entries in the array are relative to the path defined in StateDir and have a .json extension If not present, a schedules.json file in the path defined in StateDir is read to provide the devices to load A JSON file that matches the name of the JSON file specified in this parameter must be present in the path defined in StateDir	Default: schedules	N
StateDir	String	The full path of the directory containing the DevicesFile and SchedulesFile		Y
Driver	Object	Device Service-specific configuration See the supported Device Service components for the available options		N
Scheduler	String	The name of the Scheduler component to use	The name of an existing Scheduler component	Y
ThreadPool	String	The name of the ThreadPool component to use	The name of an existing ThreadPool component	Y
Bus	String	The name of the Bus component to use	The name of an existing Bus component	Y
Logger	String	The name of the Logger component to use	The name of an existing Logger component	N
ValidateProfilesOnStart	Boolean	Specify true for Xrt to validate that every profile loaded on startup is correct Specify false for no profile validation to occur on startup	Default: true	N
DiscoverInitialValues	Boolean	Specify true for Xrt to include initially discovered values in generated profiles Specify false for no initial values to be included in generated profiles	Default: false	N
AllowedFails	Unsigned Integer	The number of consecutive failed device requests after which a device is automatically marked non-operational Set to zero to disable automatic marking of devices as non-operational	Default: 0	N
DeviceDownTimeout	Unsigned Integer	Time (in seconds) before re-enabling a device which has been automatically marked non-operational Set to zero to disable automatic re-enablement of devices	Default: 0	N
AutoBatchSize	Unsigned Integer	XRT will batch together consecutive scheduled readings in groups of up to the size specified This group will then be executed as one command	Default is 0 which disables the auto-batching feature	N
AutoBatchTimeout	Unsigned Integer	XRT will batch together consecutive scheduled readings into a group until the time limit (in milliseconds) has been reached. This group will then be executed as one command	Default: 250	N