1 Introduction
This document describes features, parameters and setting possibilities of the WB169-430-V module, which is used
either for remote reading of iPERL series watermeters by Sensus equipped with 433 MHz data transmitter, or other
watermeters (*) of the ”smart” category, equipped with an 433 MHz transmitter working in Wireless M-Bus format.
The module receives messages from watermeters and broadcasts the read data to the superior Automatic Meter
Reading (AMR) system n form of 169 MHz Wireless M-Bus standard messages.
(*) Although the module is primarily intended for reading watermeters, it can also be used for reading of any other
consumption meters or sensors that send messages in 433 MHz Wireless M-Bus format.
1.1 Wireless M-BUS Communication Protocol
Wireless M-BUS is the communications protocol described by international standards EN 13757-4 (physical and
link layer) and EN 13757-3 (application layer), which is intended primarily for radio transmission of remote reading
values from consumption meters and sensors. Protocol Wireless M-BUS (hereinafter ”WMBUS”) is based on a
standard M-BUS definition (uses the same application layer as M-BUS standard), but is adapted for data transfer
via radio signals.
Communications via WMBUS protocol works in Master-Slave mode, where ”Master” is a collecting data device,
”Slave“ is a providing data device. Slave device could be integrated or external radio module transmitting data
from the meter/sensor. The communications protocol WMBUS defines several communication modes (simplex or
duplex). If working in simplex mode a ”Slave” device only transmits messages to ”Master” that these messages
receives. If working in ”bidirectional” mode, it is possible to use a reverse channel from ”Master” device to ”Slave”
device for ”Request” type of messages, that can contain e.g. request for the change of slave’s configuration.
Wireless M-BUS communications protocol partially supports repeating of the messages. If receiving from some
”Slave” device is not possible because of the low level of radio signal, the messages can be re-transmitted (repeated)
by appointed element of the radio network (repeater or slave with such functionality). Each repeated message is
marked as ”repeated message” so as not to be repeated again.
1.2 Module usage
The WB169-430-V module can be used as local communication gateway for remote reading of Sensus iPERL-
series watermeters, or other ”smart” watermeters with integrated Wireless M-Bus transmitters in the 433 MHz
band. The module receives regular radio messages with readings from watermeters within its radio-reach and
stores the readings to its memory. In pre-defined intervals the module broadcasts aggregate of received data to
the superior remote reading system (AMR) in form of Wireless M-Bus radio-messages in 169 MHz frequency band
(”INFO” messages).
The WB169-430-V module can by used for remote reading up to 20 watermeters placed in its radio-reach (that
is up to hundreds meters). Each watermeter transmits the messages with a short fixed period (e.g. iPERL every
15 seconds). The module receives data from watermeters in regular ”receiving windows”, that are opened with
preset transmitting period (e.g. every 120 minutes). Received data from each receiving window are stored into the
module memory. Immediately after closing of the receiving window the module broadcasts received data from all
watermeters to the superior system in one Wireless M-Bus message.
Each module has its table of read watermeters, where there are IDs (serial numbers) of meters that should be
read by the module. If there are other watermeters in the reach, their messages are ignored. The module supports
receiving and transmitting of messages either in open mode, or in encrypted mode. The module allows forwarding
of original alarm statuses (”flags”) from watermeters together with normal readings, or conversion of ”flags” into
the wacoSystem alarm messages, that are sent immediately.
Content of INFO-messages is configurable. The messages contain identification and current statuses of module
parameters (uptime, battery voltage, processor temperature..), list of read watermeters and current values of its
counters. The messages are broadcasted either in open mode (without encryption), or encrypted by AES-128
encryption key. The messages are transmitted on the 169.4 MHz frequency with data rate from 2.4 kbps to 19.2
kbps (according to used frequency channel). Messages can be received either by WB169-RFE communication
gateway (WMBUS Ethernet GateWay produced by SOFTLINK), or any other ”Master” device that complies with
the Wireless M-BUS EN 13757-3 / EN 13757-4 standard for 169 MHz frequency band.
The WB169-430-V module supports bi-directional communication and it is able to receive commands in Wireless
M-Bus format from the 169 MHz network. These messages can be used for setting of module parameters from the
remote server.
WB169-430-V 1
