Wireless M-Bus Range Extender /
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User Manual Version 1.0
Page 14 of 32
Recording of Wireless M-Bus Packets
Two calendar event types are used to start a Wireless M-Bus packet capture phase either in S-Mode or combined C- / T-Mode. The received
packets will be decoded according to the defined physical layer encoding Manchester, Three Out Of Six or NRZ. Every packet will be
checked for CRC errors and only valid packets will be decoded according to the given frame format A or B. The Wireless M-Bus CRCs are
stripped of to save memory and LoRa upload airtime. In the next step the packet has to pass a filter stage which compares the WM-Bus
packet header fields with a set of configured adresses (Whitelist). Finally the accepted packets are stored into an embedded flash memory.
The flash memory will be automatically erased after each LoRa upload session.
The following figure outlines the connection between WM-Bus reception Calendar Events, Filter Set ID and the Wireless M-Bus Device Filter.
Figure : Example of Wireless M-Bus packet reception, Wireless M-Bus Address Whitelist and Calendar Events
1. It is recommended to reserve some time after a reception phase for uploading of captured messages via LoRaWAN network.
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2. Monthly events which are scheduled for days that are not present in the current month e.g. 29.2, 30.2, 31.2, 31.4, 31.6, 31.9,
31.11 are scheduled for the last day of the month. Thus it is highly recommed not to schedule a Wireless M-Bus capture start or
stop event for one of these days.
