# Transmission of the daily balancing area aggregate time series from ÜNB to NB — NB view The ÜNB forms the BG-SZR (category C) daily and transmits it to the NB. The BG-SZR (category C) is formed on the basis of the ¼ h values transmitted by the MSB and the master data provided by the NB for all market locations with ÜNB aggregation responsibility. As the status per ¼ h, the BG-SZR (category C) always shows the worst status of any of the individual values in the same ¼ h. ## Process flow from the perspective of the NB \nSystem diagram: Übermittlung der täglichen Bilanzierungsgebietssummenzeitreihe vom ÜNB an NB — view of NB\n\n\nCustomer backend system\n\nMACO APP · NB\n\nMarket partner\n\n\n\n1. BG-SZR (Kategorie C)\n\nÜNB\n\nAS4\n13003\n\nLoad data for the incoming\ncheck\n\n\n2 read APIs called\n\nAPI\nlisted at the step\n\nCreate transaction\n\n\nCreate process data\n\nAPI\n"} gesamt={"\nSequence diagram: Übermittlung der täglichen Bilanzierungsgebietssummenzeitreihe vom ÜNB an NB — view of NB\n\n\nBackend (customer)\n\n\nMACO APP · NB\n\n\nÜNB\n\n\n1. BG-SZR (Kategorie C)\nAS4 · PI 13003\n\nCreate transaction\nCreate process data\n"} titel="NB" /> ## Process steps ### BG-SZR (category C)
**Check identifiers** - [13003](/en/schnittstellen/202604/pruefi/MSCONS/PI_13003) — Aggregated time series · AS4
**Flow**
  1. Message from **ÜNB** · AS4
  2. **Load data for the incoming check** - [Read market location](/en/api/202604/backend-lesen/getmarketlocationbasic#marktlokation-lesen) `GET /getMarketLocationBasic` Try it - [Read meter](/en/api/202604/backend-lesen/getcounterbasic#zahler-lesen) `GET /getCounterBasic` Try it
  3. **Write endpoint** - Transaction created — [Create process data](/en/api/202604/backend-schreiben-nb/createprocessdata#prozessdaten-erstellen) `POST /createProcessData` Try it out Creates a new transaction in the backend with the data of the incoming message.
## Process information Wording of the consolidated version, profile ch. 15.4.1, p. 213.
  1. ### Preconditions - The MaBiS-ZP is activated at the recipient by the ÜNB. - The master data for creating the BG-SZR (category C) is available to the ÜNB. - The required values from the MSB of the individual market locations are available to ÜNB by 11:00 for the previous day.
  2. ### Results The grid operator can use the transmitted BG-SZR (category C) for further processes.
  3. ### Further requirements The ÜNB must also be able to form an aggregate if not all meter reading values of all market locations are available. This must then be indicated with a status for the respective ¼ h.
  4. ### First message **ÜNB** sends “BG-SZR (category C)” (step 1). From here on, it is the turn of the party involved on this page.
  5. ### Objective The NB has received the required BG-SZR (category C) from the ÜNB on a daily basis.
## Other views of the process The same process through the eyes of the other parties involved: the same steps, each read from their point of view. - [View ÜNB](/en/prozessdoku/202604/UENB/MaBiS-uebermittlung-der-taeglichen-bilanzierungsgebietssummenzeitreihe-vom-uenb-an-nb) — ÜNB · market role UENB *The steps are the **possible** messages of this process, not a sequence — the source lists neither conditions nor alternatives. The small box on the step names the own view on the left: with **←** it receives, with **→** it sends. Collapsed steps run between other market partners.* The connector table lists no write call for these steps. Derived from the process flow: the process begins for the own role with their message, so the transaction is created. Applies to: [1](#schritt-1) For the check identifiers of these steps there is no test case in the test data set; the »Try it out« button of the write interface therefore offers no body. Applies to: [1](#schritt-1)