LEM DCBM 400 Series - 7.2.3. Transaction Readouts

Page 72/95
21January2021/Version 0
LEM International SA
Chemin des Aulx 8
1228 PLAN-LES-OUATES Switzerland
www.lem.com
The transaction must be terminated using a stop request. The necessary input to stop the active
transaction is its transactionId. Response to the stop request contains the nal data structure,
in /legal format.

The last transaction and previous ones can be retrieved from the DCBM memory.
On the HTTP/REST interface, the DCBM supports two data formats for readouts:
• LEM proprietary format, in /legal API (see §7.1)
• Certied, billable, OCMF-compliant format in /ocmf API (see 7.1) (see "3.4. Certication and
compliance")
!
For backend storage, OCMF format shall be preferred over LEM format. See "7.3.1. Energy
registering".
Four modes of access are available. All the readings of transactions are digitally signed.
  
Retrieve the last transaction (or current)
/v1/legal
/v1/ocmf
If a transaction is on-going, this request
retrieves the current transaction.
Otherwise, the last one is retrieved.
Retrieve by transactionId
(search limited to transactions)
/v1/legal?transactionId=<xyz>
/v1/ocmf?transactionId=<xyz>
With <xyz> the transactionId of the
transaction to retrieve
(search limited to  transactions)
Retrieve by internal storage index
/v1/legal/<index>
/v1/ocmf/<index>
With <index> a positive number. See
below note.
1)
Internal  in the
response to a start transaction request.
Retrieve by chronological storage index
/v1/legal/-<index>
/v1/ocmf/-<index>
With <index> = -1 the past transaction
before the latest
With <index> = -20398 the oldest
transaction stored (once storage reached
full capacity).
Table 8: Solutions for retrieving past transactions
Note:
1)
Chronological storage index is advised for retrieving all stored transactions.
Indeed, behavior of internal storage index is as follows:
• Transaction storage is a circular bu󰀨er, allowing wrap-around (see "7.2.4. Memory depth"). Internal storage indexes
can span from 0 to 20425, with a bu󰀨er gap of 27 transactions.
• Hence, retrieving all transactions through internal storage index might throw back HTTP error “404 - Not found” for
some internal storage indexes.