---
title: "System frequency (FREQ)"
method: GET
path: "/datasets/FREQ"
tags: ["BMRS Datasets"]
---

# System frequency (FREQ)

`GET /datasets/FREQ`

The endpoint provides data that has been received every 2 minutes the transmission system frequency, expressed as a hertz value for one or more spot times within that 2 minute period.
The default output will be the latest published data.
            
A maximum limit of 24 hours is applied to this endpoint to limit response size. Use the streaming version
for larger response sizes.

## Query parameters

- `measurementDateTimeFrom` string, date-time
- `measurementDateTimeTo` string, date-time
- `format` 'json' | 'xml' | 'csv'

## Response `200`

Data retrieved

- InsightsApiModelsResponsesDatasetResponse1InsightsApiModelsResponsesMiscDatasetRowsSystemFrequency
  - `data` InsightsApiModelsResponsesMiscDatasetRowsSystemFrequency[], nullable
    - `dataset` string, nullable
    - `measurementTime` string, date-time
    - `frequency` number, double

## Other responses

- `400` — Error with query parameters - see response for details
- `429` — Too many requests
- `500` — Server error - please try again later

---

[API](https://skmtc.net/elexon/apis/bmrs-insights.md) · [All operations](https://skmtc.net/elexon/apis/bmrs-insights/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/elexon/bmrs-insights/versions/d94e9edb295e/schema)