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The storage number does group value by points in time.
| Storage Number | When? |
|---|---|
| 0 | At time of reading |
| 1 .. n | Historic values, e.g. Monthly or Due Date Values |
There can be multiple value types inside a single storage number, typical values are:
| Value type | Examples | Meaning |
|---|---|---|
Date Time & Date | 31.12.2022 01.02.2023 23:55:00 | All values of the storage number relate to this time. |
| Meter value | Volume / Energy / Temperature / H.C.A. / etc. e.g. 20.4 °C | The value measured by the meter |
| Error Value | [0 1 0 0 0 0 0 0] | Ofen manufacturer specific error flags. Mostly used in storage number 0, but can also appear in others. |
| Any other | Some meters have other value types |
Encryption
Wireless M-Bus Telegrams are usually encrypted 
and must be decrypted 
using a 16-Bit key.
When received by the Lobaro Plattform, you can configure decryption keys that are applied up on reception (see: wMbus Keys).
Telegram Coding
Telegram type A
- Always for wMBUS S1 mode
- Always for wMBUS T1 mode
- Possible for wMBUS C1 mode
- The detection is done via the syncword on phy level by the receiver
L-Field
The first byte of the first block is the length field. The field specifies the number of subsequent user bytes, including control and address bytes, but not CRC bytes. If ((L-9) MOD 16) is not zero, then the last block must contain ((L-9) MOD 16) data bytes +2 CRC bytes. All other blocks, except the first block, must always contain 16 data bytes + 2 CRC bytes.
CRCs
- First crc after 10 bytes
- Then every 16 bytes one CRC of length 2 (= 18)
- Plus one crc at the end (unless ending on 16 byte block)
Telegram type B
- Possible for wMBUS C1 mode
- The detection is done via the syncword on phy level by the receiver
L-Field
The first byte of the first block is the length field. The field sets the number of all subsequent bytes, including all CRC bytes.
CRCs
The link layer check of telegram format B is performed on a maximum of 128 bytes, including the CRC field. Telegrams with a length of up to 128 bytes, including CRC and L field, contain a single CRC field covering both the first and the second block. Telegrams with a length between 131 bytes and 256 bytes (maximum length) contain two CRC fields, with the second CRC field covering the optional block. The format of the different blocks in the telegram is defined below.