# GeLi_Gas 2.0 ch. 4.1.1.1 Collection of metered values — LF view ## Process flow from the perspective of the LF \nSystem diagram: GeLi_Gas 2.0 Kap. 4.1.1.1 Erhebung von Messwerten — view of LF\n\n\nCustomer backend system\n\nMACO APP · LF\n\nMarket partner\n\n\n\nProcess trigger received\n\nSTART_ERHEBUNG_MESSWE\nRTE\n\nAPI\n\n\n\nNB\n\nAS4\n13002\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\n"} gesamt={"\nSequence diagram: GeLi_Gas 2.0 Kap. 4.1.1.1 Erhebung von Messwerten — view of LF\n\n\nBackend (customer)\n\n\nMACO APP · LF\n\n\nNB\n\n\nSTART_ERHEBUNG_MESSWERTE\nTrigger event\n\n\nAS4 · PI 13002\n\nUpdate transaction\nUpdate process data\n"} titel="LF" /> ## Process steps ### Meter reading (Gas)
**Check identifiers** - [13002](/en/schnittstellen/202610/pruefi/MSCONS/PI_13002) — Meter reading (gas) · AS4
**Flow**
  1. **Prozessauslöser** [`START_ERHEBUNG_MESSWERTE`](/en/api/202610/ausloeser-lf/start-erhebung-messwerte) \"\n ],\n \"lokationsId\": \"\"\n }\n ],\n \"ZAEHLER\": [\n {\n \"zaehlernummer\": \"\"\n }\n ]\n },\n \"transaktionsdaten\": {\n \"absender\": {\n \"rollencodenummer\": \"\"\n },\n \"anfrageReferenz\": \"\",\n \"empfaenger\": {\n \"rollencodenummer\": \"\"\n },\n \"kategorie\": \"\",\n \"sparte\": \"\"\n },\n \"zusatzdaten\": {\n \"eventname\": \"START_ERHEBUNG_MESSWERTE\",\n \"prozessId\": \"\"\n }\n}"} security={[{"bearer": []}]}>Ausprobieren The backend triggers this step with this event.
  2. Message to **NB** · AS4
  3. **Write endpoint** - Transaction updated — [Update process data](/en/api/202610/backend-schreiben-lf/updateprocessdata#prozessdaten-aktualiseren) `POST /updateProcessData` Try it out Updates the existing transaction in the backend once the message has been created.
## Process information
  1. ### First message The party involved on this page is itself the sender: “” to **NB** (the first step).
## 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 NB](/en/prozessdoku/202610/NB/geli-gas-2-0-geli-gas-2-0-kap-4-1-1-1-erhebung-von-messwerten) — NB *The source provides no use case profile for this process — objective, precondition and result are not recorded there.* *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.* :::caution{title="Step sequence reconstructed"} For this process, the BNetzA consolidated version carries no sequence diagram. The steps are reconstructed from the BDEW check identifier table: grouped by the designation, ordered by the process step. The method agrees with the consolidated version in 200 of 200 cases that can be cross-checked — the individual line is nevertheless not editorially reviewed. Check it against the rulebook before adopting it into an implementation specification. ::: The source does not name this step; the heading names the use cases of its messages. Applies to: [—](#schritt-ohne-nr-0)