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Introduction
This document describes features, parameters and setting possibilities of the WS868-PLE-I module, which is used
for reading of Elster BK-G series gas-meters and for radio-broadcasting of the data from the gas-meter to the
superior remote reading system in form of Sigfox standard messages.
1.1
Sigfox communication network
Sigfox communication network
is a global radio frequency (RF) communication system intended for collecting
data from the huge number of terminal devices that transmit only a very limited amount of data. This kind of
network services are commonly referred as
”
Internet of Things” (”IoT”).
Sigfox technology (including communication protocol) is optimizing for
maximum radio range
, that enables
building of country wide RF networks with a maximum cost effectivity. Unification of technology, global register of
identification addresses as well as central registration and control system enable interconnection of national networks
(
”
roaming”) into one global Sigfox network.
The module is designed for using in free
868 MHz frequency band
with maximum transmitting power of
25
mW
that is commonly used in European countries. Maximum reach of Sigfox services in this band for devices
with maximum transmitting power in open terrain is in range of tens of kilometers. This extensive range is enabled
by using of ultra-low modulation frequency (Ultra Narrow Band Modulation) where communication sub-channel
bandwidth is just 100 - 600 bps (Baud). As the messages are transmitted with such extremely low speed, Sigfox
message was invented as short as possible with maximum length of 26 Byte (maximum data content of 12 Byte).
Optimized length of message has positive influence on the terminal device energy consumption during transmitting
and receiving.
Sigfox network supports also
bi-directional communication
, if
”
Downlink” service for transfer of data in reverse
direction is allowed, in earmarked time interval the Sigfox base station can deliver to terminal device a special
downlink radio-message containing configuration commands.
National Sigfox RF network consists of number of base stations, that are connected by data channels into one central
node (
”
star” type topology). The messages from Sigfox RF network are transferred from Sigfox central network
server to the application servers of authorized users through the
unified data interface
via public Internet.
1.2
Module usage
The WS868-PLE-I module can be used for remote reading of Elster BK-G series residential gas-meters that are
equipped with special slot (
”
lock”) for external remote reading modules (e.g. IN-Z61) in the lower side of its
counter. The module is equipped with one magnetic sensor for registration of gas-meter counter revolution and
one magnetic sensor for detection of detachment from gas-meter (
”
Tamper”). The module continuously registers
revolving of gas-meter pivotal wheel into its internal counter and broadcasts info-messages with current status of
gas-meter counter in form of Sigfox standard radio-messages (hereinafter
”
INFO-message”). The INFO-messages
contain also service information about tamper status, battery voltage and processor temperature.
The INFO-messages are transferred through the Sigfox network to the central network server (
”
Back-End”), from
which there are forwarded to assigned IP-address of their addressee through the Internet. The addressee of the
messages is an application server of remote reading service operator, where the messages are decoded and processed.
The WS868-PLE-I module supports
bi-directional communication
that can be used for remote setting of counter
initial value and for change of broadcasting period. Required remote configuration values are delivered to the module
by special radio-messages of
”
Downlink” service, that are assembled by
”
Back-End” server on the application server
request and broadcasted by responsible base station.
1.3
Hardware features
The module is enclosed in plastic casing designed for mounting directly to the BK-G series gas-meter counter slot
reserved for remote reading modules. The device is not suitable for using in exteriors without additional protection.
The module is power supplied by internal battery with up to 10 years lifetime for frequency of 4 - 6 broadcastings
per day. Battery lifetime can be negatively influenced by shorter broadcasting period, or by storing and operation
in sites with the temperatures exceeding the recommended range. The module can be controlled and configured
either by configuration cable, or wirelessly - by infra-red remote control with using of optical converter.
External appearance of the WS868-PLE-I module is shown in the figure
. Position of infrared sensor for wireless
configuration is marked by green arrow.
WS868-PLE-I
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