Built-in GET/SET RPC Methods

Every telemetry and attribute parameter has GET and SET methods automatically, based on the path defined in the connector configuration.

For example, given a timeseries entry:

{
  "timeseries": [
    {
      "key": "temperature",
      "path": "${ns=3;i=1001}"
    }
  ]
}

Read the current value of a node by its OPC-UA node ID:

get ns=3;i=1001;

Response:

{"result": 25.34}

Write a numeric value to a node:

set ns=3;i=1001; 23

Write a string value to an attribute node (e.g. set model to T3000):

set ns=3;i=1008; T3000;

Response:

{"success": "true", "code": 200}

Read the value of a Modbus slave register:

get type=<type>;functionCode=<functionCode>;objectsCount=<objectsCount>;address=<address>;

Example — read a 16-bit integer from register 1 (outdoor temperature):

get type=16int;functionCode=3;objectsCount=1;address=1;

Response:

{"result": {"value": 13}}

Write a value to a Modbus slave register:

set type=<type>;functionCode=<functionCode>;objectsCount=<objectsCount>;address=<address>;value=<value>;

Example — write 80 to register 2 (room light level):

set type=16int;functionCode=6;objectsCount=1;address=2;value=80;

Response:

{"result": {"value": "80"}}

Verify by reading the register back:

get type=16int;functionCode=3;objectsCount=1;address=2;

Response:

{"result": {"value": 80}}

Subscribe to a response topic and publish a request to read a value:

get requestTopicExpression=<requestTopic>;responseTopicExpression=<responseTopic>;value=<value>;

Example — read room light level from data/light_level, receiving the response on data/response:

get requestTopicExpression=data/get_light_level;responseTopicExpression=data/response;value=${params};

Publish a message to an MQTT topic:

set requestTopicExpression=<requestTopic>;value=<value>;

Example — set room light level to 80:

set requestTopicExpression=data/set_light_level;value=80;

Verify by sending a GET request:

get requestTopicExpression=data/get_light_level;responseTopicExpression=data/response;value=${params};

Read a property value from a BACnet device:

get objectType=<objectType>;objectId=<objectId>;propertyId=<propertyId>;

Example — read the current room light level (analogValue, object 1, presentValue):

get objectType=analogValue;objectId=1;propertyId=presentValue;

Response:

{"result": "30.5"}

Write a property value to a BACnet device:

set objectType=<objectType>;objectId=<objectId>;propertyId=<propertyId>;priority=<priority>;value=<value>;

At least one of value or priority must be provided. If value is omitted, the connector sends a relinquish command with a Null value.

Example — set the room light level to 30.9:

set objectType=analogValue;objectId=1;propertyId=presentValue;value=30.9;

Response:

{"result": "{\"status\":\"ok\"}"}

Verify with GET:

get objectType=analogValue;objectId=1;propertyId=presentValue;

Response:

{"result": "30.9"}

Send a GET request to a REST endpoint:

get requestUrlExpression=<url>;value=<value>;

Example — read the room light level from http://127.0.0.1:8000/light-level:

get requestUrlExpression=http://127.0.0.1:8000/light-level;value=${params};

Response:

{"result": {"light-level": 30}}

Send a POST (or other HTTP method) request to a REST endpoint:

set requestUrlExpression=<url>;value=<value>;HTTPMethod=<method>;

Example — set the room light level to 80:

set requestUrlExpression=http://127.0.0.1:8000/light-level;value=80;HTTPMethod=POST;

Response:

{"result": {"status": "ok"}}

Verify with GET:

get requestUrlExpression=http://127.0.0.1:8000/light-level;value=${params};

Response:

{"result": {"light-level": 80}}

Send a GET request to an external API endpoint configured in the connector:

get requestUrlExpression=<path>;

Example — read the room light level from the configured base URL:

get requestUrlExpression=light-level;

Response:

{"result": "{\"light-level\":30}"}

Send a POST (or other HTTP method) request to an external API endpoint:

set requestUrlExpression=<path>;value=<value>;httpMethod=<method>;

Example — set the room light level to 80:

set requestUrlExpression=light-level;value=80;httpMethod=POST;

Response:

{"result": "{\"status\":\"ok\"}"}

Verify with GET:

get requestUrlExpression=light-level;

Response:

{"result": {"light-level": 80}}

Read a file from the FTP server:

get filePath=<filePath>;

Example — read light_level.txt:

get filePath=./light_level.txt;

Response:

{"result": 30}

Write a value to a file on the FTP server:

set filePath=<filePath>;value=<value>;

Example — update light_level.txt to 80:

set filePath=./light_level.txt;value=80;

Response:

{"result": "{\"success\": true}"}

Verify with GET:

get filePath=./light_level.txt;

Response:

{"result": 80}

The Socket connector supports only the SET method — sending data to a TCP socket endpoint.

Send data to a TCP socket:

set address=<address>;port=<port>;value=<value>;

Example — send a light level of 80 to a sensor listening on 192.168.0.200:50003:

set address=192.168.0.200;port=50003;value=80;

Response:

{"result": "ok"}

Socket SET — value sent and acknowledged by the TCP endpoint. Sensor side — the new value received by the device.