Calling Device Services

Typical Scenario

The device profile file defines commands that the IoT platform can deliver to a device. When an NA needs to configure or modify the service attributes of a device, the NA can call this API to deliver commands to the device.

The IoT platform does not cache commands but delivers commands directly. When a device is offline, the commands fail to be delivered. The formats of the delivered command need to be defined by the NAs and devices. The IoT platform encapsulates and transparently transmits the commands over this API.

NOTE:

Currently, this API can be used to deliver commands only to gateways equipped with the IoT Agent or AgentLite to control non-directly connected devices under the gateways.

API Function

This API is used to immediately deliver commands to gateways equipped with the IoT Agent or AgentLite to control the gateways. This API applies to devices registered with the current application.

API Description

1	InvokeDeviceServiceOutDTO invokeDeviceService(String deviceId, String serviceId, CommandDTO2 commandDTO, String appId, String accessToken) throws NorthApiException

Parameter Description

Parameter	Mandatory or Optional	Type	Location	Description
deviceId	Mandatory	String(1-64)	path	Identifies a device.
serviceId	Mandatory	String(1-64)	path	Uniquely identifies a service.
commandDTO	Mandatory	CommandDTO2 structure	body	For details, see CommandDTO2 structure.
appId	Mandatory	String	query	If the device belongs to the current application, set this parameter to null. Otherwise, set this parameter to the ID of the authorized application.
accessToken	Mandatory	String	header	If the Periodically Refreshing a Token API is called, set this parameter to null. Otherwise, set this parameter to the accessToken obtained by the Authentication API.

CommandDTO2 structure

Parameter	Mandatory or Optional	Type	Location	Description
header	Mandatory	CommandNA2CloudHeader	body	For details, see CommandNA2CloudHeader structure.
body	Optional	Object	body	Indicates the message body. The content of the JsonObject is a list of key-value pairs. Every key is the paraName of a command defined in the profile.

CommandNA2CloudHeader structure

Parameter	Mandatory or Optional	Type	Location	Description
requestId	Optional	String(0-128)	body	Identifies a command. The value of this parameter must be unique.
mode	Mandatory	Enum	body	Indicates whether an ACK message is required. NOACK: No ACK message is required. ACK: An ACK message is required. Other values: invalid
from	Optional	String(128)	body	Indicates the address of the message sender. Request initiated by an application: /users/{userId} Request initiated by an NA: /{serviceName} Request initiated by the IoT platform: /cloud/{serviceName}
toType	Optional	Enum	body	Indicates the type of the message recipient. The value options are CLOUD and GATEWAY.
to	Optional	String(128)	body	Indicates the address of the message recipient.
method	Mandatory	String(1-32)	body	Indicates the command name. For example, a DISCOVERY command is used to discover non-directly connected devices, and a REMOVE command is used to delete non-directly connected devices.
callbackURL	Optional	String(1024)	body	Indicates the callback URL.

Response Parameters

InvokeDeviceServiceOutDTO structure

Parameter	Type	Description
status	String(128)	Indicates the command status. sent: The command has been sent. delivered: The command has been delivered. This value is returned when toType is set to CLOUD. failed: The command fails to be delivered. This value is returned when toType is set to CLOUD.
timestamp	String(128)	Indicates the timestamp used for sending a command. The value is in the format of yyyyMMdd'T'HHmmss'Z'. An example value is 20151212T121212Z.
requestId	String(128)	Identifies a device command. When toType is set to GATEWAY, if requestId is carried in a request, the response carries the same requestId as the request; if requestId is not carried in a request, the IoT platform allocates a sequence number for the response. When toType is set to CLOUD, the value of this parameter is null.

Parameter

Type

Description

status

String(128)

Indicates the command status.

sent: The command has been sent.
delivered: The command has been delivered. This value is returned when toType is set to CLOUD.
failed: The command fails to be delivered. This value is returned when toType is set to CLOUD.

timestamp

String(128)

Indicates the timestamp used for sending a command. The value is in the format of yyyyMMdd'T'HHmmss'Z'. An example value is 20151212T121212Z.

requestId

String(128)

Identifies a device command.

When toType is set to GATEWAY, if requestId is carried in a request, the response carries the same requestId as the request; if requestId is not carried in a request, the IoT platform allocates a sequence number for the response.
When toType is set to CLOUD, the value of this parameter is null.

Error Codes

HTTP Status Code	Error Code	Error Description	Remarks
200	100203	The application is not existed.	The application does not exist. Recommended handling: Check whether appId carried in the HTTP request header is correct. Check whether appId in the request path (URL) is correct.
200	100217	The application hasn't been authorized.	The application has not been authorized. Recommended handling: In scenarios where applications are not authorized, ensure that request parameter appId is null.
200	100418	The deviceData is not existed.	The device data does not exist. Recommended handling: If deviceId carried in the request is incorrect, check whether deviceId belongs to appId or whether deviceId is incorrect. Check whether appId carried in the header contains deviceId. If the URL contains the optional parameter appId, check whether the value of appId is correct.
200	100428	The device is not online.	The device is not online. Recommended handling: Check whether the connection between the device and the gateway is normal.
200	100432	The device command is muted.	The device command is muted. Recommended handling: Check whether the command carried in the API request parameter method is correct.
400	100022	The input is invalid.	An input parameter is invalid. Recommended handling: Check whether parameters carried in the API call request are valid.
400	102203	CommandName is invalid.	The command name is invalid. Recommended handling: Check whether the command carried in the API request parameter method is correct.
403	100450	The gateway is not online.	The gateway is offline. Recommended handling: Check whether the connection between the gateway and the IoT platform is normal.
403	1010009	app throttle exceed.	The NA calls the API at a frequency that exceeds the flow control threshold (100 calls per minute by default). Recommended handling: Contact IoT platform maintenance personnel to adjust the flow control threshold or control the API call frequency.
403	1010005	App_key or access_token is invalid.	The access token is invalid. Recommended handling: Check whether accessToken carried in the API request is correct.
404	100444	The serviceType is not exist.	The service type does not exist. Recommended handling: Check whether the service type carried in the API request parameter toType is correct.
500	100001	Internal server error.	An internal server error occurs. Recommended handling: An internal error occurs on the IoT platform. Contact IoT platform maintenance personnel.
500	100023	The data in database is abnormal.	The database is abnormal. Recommended handling: An internal error occurs on the IoT platform. Contact IoT platform maintenance personnel.
500	50252	Internal server error.	An internal server error occurs. Recommended handling: An internal error occurs on the IoT platform. Contact IoT platform maintenance personnel.
503	100501	Congestion occurs, and the current network has been flow-controlled	Congestion occurs. The current network is under flow control.