Report Objects

Document Context

• Purpose: Documents raw DLMS/COSEM objects endpoint for accessing meter-native OBIS codes and understanding available measurements
• When to use: Debugging meter communication, mapping custom scalers, understanding meter capabilities, developing OBIS code parsers
• Prerequisites: Knowledge of DLMS/COSEM protocol, OBIS code structure, energy meter communication standards
• Related to: Report polling endpoint, meter communication settings, OBIS reference documentation, custom scalers
• Validates against: Live OBIS object lists from Swiss smart meters via 192.168.99.114

Key Facts

• Endpoint: /api/v1/report/objects
• Methods: GET only
• Authentication: HTTP Authentication (when device protection enabled)
• Response format: JSON with OBIS logical names and DLMS classes
• Data source: Direct from meter COSEM interface (not processed by device)
• Use cases: Diagnostics, custom parsing, meter capability discovery
• OBIS classes: Class 1 (data), Class 3 (register), Class 40 (push objects)
• Meter dependency: Requires active meter connection and communication

Endpoint Details

This endpoint exposes raw DLMS/COSEM objects (OBIS codes) reported by the meter. It is useful for diagnostics, understanding available measurements, and mapping scalers/units.

Endpoint	api/v1/report/objects
Method	GET
Response content type	application/json

Authentication

When a Web UI password is set, HTTP endpoints require HTTP authentication.

Firmware 1.10.X and later: Uses HTTP Digest authentication - Server challenges with WWW-Authenticate: Digest … (realm is the device hostname) - Algorithm: MD5-sess (device advertises MD5-sess; integrity variant supported) - qop: auth (and optionally auth-int for requests with body integrity) - Nonce and opaque are issued by the device; the client must include cnonce and increment nc - Expired nonce: server may return 401 with WWW-Authenticate: …, stale=true. In that case, retry the same request once using the new server challenge, a new cnonce, and reset nc=00000001.

Firmware before 1.10.X: Uses HTTP Basic authentication - Server challenges with WWW-Authenticate: Basic realm="..." - Credentials are base64-encoded in Authorization: Basic <encoded-credentials>

Recommended approach: Use --anyauth in curl to automatically detect and use the appropriate method:

curl --anyauth -u ":<password>" http://whatwatt-ABCDEF.local/api/v1/system

Example response (from device 192.168.99.114)

{
  "objects": [
    {
      "logical_name": "0-8:25.9.0",
      "class": 40,
      "size": 28,
      "push_object_list": [
        { "logical_name": "0-8:25.9.0", "class": 40, "attribute": 2, "data_index": 0 },
        { "logical_name": "0-0:42.0.0", "class": 1,  "attribute": 2, "data_index": 0 },
        { "logical_name": "1-1:1.8.0", "class": 3,  "attribute": 2, "data_index": 0 },
        { "logical_name": "1-1:2.8.0", "class": 3,  "attribute": 2, "data_index": 0 },
        { "logical_name": "1-1:3.8.0", "class": 3,  "attribute": 2, "data_index": 0 },
        { "logical_name": "1-1:4.8.0", "class": 3,  "attribute": 2, "data_index": 0 },
        { "logical_name": "0-0:96.14.0", "class": 1, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:1.7.0", "class": 3,  "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:2.7.0", "class": 3,  "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:32.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:52.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:72.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:31.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:51.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-0:71.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:21.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:41.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:61.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:22.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:42.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:62.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:23.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:43.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:63.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:24.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:44.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "1-4:64.7.0", "class": 3, "attribute": 2, "data_index": 0 },
        { "logical_name": "0-0:96.13.0", "class": 1, "attribute": 2, "data_index": 0 }
      ]
    },
    { "logical_name": "0-0:42.0.0",  "class": 1, "tag": 9,  "size": 16, "value": "4C475A31303330373834383535323034" },
    { "logical_name": "1-1:1.8.0",  "class": 3, "tag": 21, "size": 8,  "value": 75133, "unit": 30, "scaler": 0 },
    { "logical_name": "1-1:2.8.0",  "class": 3, "tag": 21, "size": 8,  "value": 25414, "unit": 30, "scaler": 0 },
    { "logical_name": "1-1:3.8.0",  "class": 3, "tag": 21, "size": 8,  "value": 82328, "unit": 32, "scaler": 0 },
    { "logical_name": "1-1:4.8.0",  "class": 3, "tag": 21, "size": 8,  "value": 19481, "unit": 32, "scaler": 0 },
    { "logical_name": "0-0:96.14.0", "class": 1, "tag": 9,  "size": 8,  "value": "5241544531000000" },
    { "logical_name": "1-0:1.7.0",  "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-0:2.7.0",  "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-0:32.7.0", "class": 3, "tag": 20, "size": 8,  "value": 234,   "unit": 35, "scaler": 0 },
    { "logical_name": "1-0:52.7.0", "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 35, "scaler": 0 },
    { "logical_name": "1-0:72.7.0", "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 35, "scaler": 0 },
    { "logical_name": "1-0:31.7.0", "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 33, "scaler": -2 },
    { "logical_name": "1-0:51.7.0", "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 33, "scaler": -2 },
    { "logical_name": "1-0:71.7.0", "class": 3, "tag": 20, "size": 8,  "value": 0,     "unit": 33, "scaler": -2 },
    { "logical_name": "1-4:21.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-4:41.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-4:61.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-4:22.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-4:42.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-4:62.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 27, "scaler": 0 },
    { "logical_name": "1-4:23.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 29, "scaler": 0 },
    { "logical_name": "1-4:43.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 29, "scaler": 0 },
    { "logical_name": "1-4:63.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 29, "scaler": 0 },
    { "logical_name": "1-4:24.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 29, "scaler": 0 },
    { "logical_name": "1-4:44.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 29, "scaler": 0 },
    { "logical_name": "1-4:64.7.0", "class": 3, "tag": 6,  "size": 4,  "value": 0,     "unit": 29, "scaler": 0 },
    { "logical_name": "0-0:96.13.0", "class": 1, "tag": 9,  "size": 21, "value": "436F6E73756D6572204D6573736167652054657874" }
  ]
}

Tip: See OBIS reference to interpret logical names and DLMS units.

Field reference

Base fields for every object:

Field	Type	Description
objects[]	array	List of DLMS/COSEM objects present in the last report
objects[].logical_name	string	OBIS code in A-B:C.D.E notation
objects[].class	uint	COSEM class id (e.g., 1=Data, 3=Register, 4=Extended Register, 8=Clock, 40=Push setup)

Class-specific fields:

• Class 1 — Data
• tag (uint): DLMS data type tag
• size (uint): payload length

• value (string/number): value; OCTET STRINGs are hex-encoded; DATE_TIME rendered as ISO8601 local time

• Class 3 — Register (scalable values)

• tag (uint), size (uint)
• value (number)
• unit (uint): DLMS unit id (see OBIS appendix)

• scaler (int): power-of-ten exponent; physical = value × 10^scaler

• Class 4 — Extended Register

• All fields of Class 3, plus:
• status (object): { tag, size, value }

• captired_time (string): ISO8601 local timestamp captured by meter (note: key name as exposed by API)

• Class 8 — Clock

• value (string): ISO8601 local time
• time_zone (int)

• status (int)

• Class 40 — Push setup

• size (uint): number of items
• push_object_list (array): items with fields { logical_name, class, attribute, data_index }

Notes

• Availability depends on the meter protocol (DLMS/COSEM). Non-COSEM meters may return fewer objects.
• For string OCTET values (tag 9), you can decode hex to ASCII to obtain text (e.g., meter identifiers, messages).
• Use Current scalers or Custom scalers to adjust presentation units.