Datapoint Type

Owned by Nina Cardillo
10-Jan-2024
8 min read

Represents the data type for a datapoint. A data type defines the size, encoding, scaling, range, resolution, and units for data values of the specified type.  Known data types are initially published on the IAP/MQ feedback channel by the resource publisher.

Two examples of data types:

  • A simple data type for a percentage value can specify a one-byte unsigned-integer value with a range from 0 to 100 in steps of 0.01 and a unit of “%”. 
  • A more complex example including a physical measurement unit is a 2-byte signed integer temperature value with a range from 273.15 to 7000 degrees Kelvin in steps of 0.01 degrees.

More examples are listed below.

IAP/MQ Mapping

For mapping the GET request to IAP/MQ, see Data Type Definitions. For mapping the PUT request to IAP/MQ, support for changeable types for a datapoint is supported if the protocol is LON and the datapoint has a property with a SCPTnvType or nvType type. To change the type, fetch the type metadata based on the new type identifier, and write the new type metadata to the type_program_id, type_scope, type_index, type_category, type_length, scaling_factor_a, scaling_factor_b, and scaling_factor_c fields of the SCPTnvType or nvType type property.

URI Definition

Method         

URI and Fields

GET


/iap/devs/{id}/if/{block}/{block_index}/{datapoint_name}/type

Returns the data type of the specified datapoints.

XIFname vs Instance Name

  • The block path element uses the block XIFname.
  • The datapoint_name path element uses the datapoint instance name.

Path Parameters

The value_param path element allows you to specify a value. 

The optional path parameters for the id, block, block_index, and datapoint_name path elements are listed on the Path Parameters page.

Query Parameters

  • pg – page number
  • sz – page size
  • xs – snapshot number

Success response 

Collections of datapoints types.

Examples

https://localhost/iap/devs/2/if/*/*/*+name=+^nvoP/type

RESPONSE:
[
    {
        "deviceId": "2",
        "blocks": [
            {
                "block": "device/0",
                "datapoints": [
                    {
                        "name": "nvoPsumtotal_kW",
                        "type": {
                            "id": "SNVT_count_f"
                        }
                    },
                    {
                        "name": "nvoPMaxxl_LM",
                        "type": {
                            "id": "SNVT_trans_table"
                        }
                    },
                    {
                        "name": "nvoPsum_kW",
                        "type": {
                            "id": "SNVT_count_f"
                        }
                    },
                    {
                        "name": "nvoPsumtotal_kW2",
                        "type": {
                            "id": "SNVT_count_f"
                        }
                    },
                    {
                        "name": "nvoPower",
                        "type": {
                            "id": "SNVT_str_int"
                        }
                    },
                    {
                        "name": "nvoPF",
                        "type": {
                            "id": "SNVT_trans_table"
                        }
                    },
                    {
                        "name": "nvoPF_2",
                        "type": {
                            "id": "SNVT_trans_table"
                        }
                    },
                    {
                        "name": "nvoP",
                        "type": {
                            "id": "SNVT_trans_table"
                        }
                    },
                    {
                        "name": "nvoPowerAlarm",
                        "type": {
                            "id": "SNVT_state_64"
                        }
                    },
                    {
                        "name": "nvoP_2",
                        "type": {
                            "id": "SNVT_trans_table"
                        }
                    },
                    {
                        "name": "nvoPMaxxl",
                        "type": {
                            "id": "SNVT_trans_table"
                        }
                    }
                ]
            }
        ]
    }
]

PUT


/iap/devs/{id}/if/{block}/{block_index}/{datapoint_name}/type

Updates the type of the specified datapoints for datapoints that support changeable types.

XIFname vs Instance Name

  • The block path element uses the block XIFname.
  • The datapoint_name path element uses the datapoint instance name.  

Path Parameters

The type path element allows you to specify a type that will be applied to specified datapoints. 

The optional path parameters for the id, block, block_index, and datapoint_name path elements are listed on the Path Parameters page.

Success response 

Response code 200 in case of success or some error code otherwise.

Examples

https://localhost:8443/iap/devs/2/if/device/0/nvoPower/type


REQUEST BODY:
SNVT_str_int


RESPONSE:
Response code 200


Queries

You can include queries with your IAP/REST request to specify a selection rule for your request.  As described in Queries and Parameters, you can specify a query as a query parameter  appended to the end of your URI preceded with a "?" character, or as a path parameter within a path element of the path component.

The optional path parameters for the id, block, block_index, and datapoint_name path elements are listed on the Path Parameters page.