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MBUS User Manual (ver 2.01)
MBUS USER MANUAL
9 MBUS4 Extra Features
9.1 Antenna tuning feature
The embedded antenna tuning feature inside the MBUS4 module will make the antenna tuning for 169MHz in a
customer specific design easy. See White Papers and Application Note on antenna tuning at Radiocrafts web
page.
https://radiocrafts.com/uploads/WP008_Antenna_Selection_Guide.pdf
https://radiocrafts.com/uploads/AN025_Tuning_the_Antenna_with_Antenna_Tuning_Feature.pdf
9.2 Italian CIG extension of Wireless M-Bus
The Italian “CIG Interchangeability Task Force” has published UNI/TS 11291-11-4, Gas measurement systems –
Hourly based gas metering systems, Part 11-4, Communication profile PM1. This is a companion standard, on top
of EN 13757-4 mode N and EN 13757-3 but using DLMS / COSEM as application layer. It contains some additional
requirements to EN13757-4, such as Listen Before Talk (LBT) and output power control in fine steps. This is
supported by MBUS4, and can be enabled through configuration memory parameters.
To enable the output power control in fine steps, set PA_TABLE_EXTENDED > 0. This is the default value, and
can be set from 1 to 19 (or 20 in case of VHP variant). It is possible to change the output power by using the ‘P’
command. The output power changes approximately 3 dB for each step. See Data Sheet for details. If
PA_TABLE_EXTENDED = 0, the module is backward compatible using the 5 steps in RF_POWER.
The LBT feature is enabled by setting LBT_ENABLE = 0x01. The following parameters configure the LBT:
LBT_RSSI_THRESHOLD, LBT_MAX_ATTEMPT, LBT_BO_PERIOD, LBT_BO_FLAT, LBT_MAX_DELAY. These
parameters should be set according to CIG recommendations.
The host controller may send 0xFA to override LBT for the following message. It applies only for one message and
is automatically cleared after this one transmission.
If the LBT algorithm fails, a command/result message is sent from the module on UART. The result message is
0x01 for failure. After successful TX, the 0x00 is sent. This result message is sent always when LBT is enabled,
even if it is overridden.
Note!
CIG only use Frame Format B, so PREAMBLE_LENGTH must be set to 0x02.
9.3 Category 1 receiver
In some cases it is advisable to trade off some sensitivity for better selectivity and blocking properties. In noisy
environments the radio communication range is not limited by thermal noise, but interference from other strong
transmitters. In this case it is possible to configure the module for Category 1 receiver settings giving increased
blocking properties as specified in EN 300220. To enable this feature, set CAT1_ENABLE = 0x01.
9.4 Wize Protocol
Offered as a separate module: RC1701HP-WIZE
– separate UM & DS.
The Wize Alliance founded by GROF, Suez and Sagemcom specified the Wize protocol, a companion standard
based on Wireless M-Bus mode N (169MHz) as used the GRPF and Suez water meter reading.
