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The SWAN2-R from WEPTECH is a battery-operated NB IoT Cat 1 gateway with the function of receiving wM-Bus / OMS meter telegrams and transmitting them to an IoT server via mobile radio using the NB1 standard for monitoring and/or billing purposes.

A key criterion here is the requirement for the most energy-efficient reception and transmission of meter data and therefore the longest possible battery life for the gateway. The ratio of the gateway's energy requirement is approx. 70 % of the receiving power and 30 % of the transmitting power.

Another important functionality of the SWAN gateway is the detection of an alarm message from the meter. For example, OMS-compliant water meters can detect sudden large deviations in consumption, e.g. in the event of a leak, and generate a corresponding alarm message to the server.

The difficulty in implementing these functionalities is therefore to keep the configured receive window of the gateway as short as possible and to synchronize it with the transmission interval of the counter telegrams. This is even more important when it comes to receiving and sending meter telegrams as frequently as possible, as a high reception frequency over a long reception window considerably reduces the battery life of the gateway.

This problem was successfully solved by the introduction of the DIN EN 13757-4 standard. The standard describes the technical implementation for the transmission of meter data, based on which the time of the next transmission of meter data can be predicted by the SWAN gateway. The meter protocol contains a status byte with the information after which period the next meter telegram will be sent. This information can be interpreted by the SWAN2 gateway and allows the power consumption for the next reception - just-in-time - to be switched on again for a short reception window.

Furthermore, in combination with the OMS Specification Vol. 2 (7.2.3), a function has also been implemented that allows data transmission to the server to be triggered directly in the event of an alarm message from a meter. The alarm message is attached to the meter telegram and can be reliably recognized by SWAN Gateway on the basis of a status byte in the OMS telegram.

Here are two cases from practice: For example, the early detection of a leak (e.g. in the event of a burst water pipe in public buildings at the weekend) enabled a rapid response time and minimized the damage to the building.

In another curious case in a municipal daycare center, the leak was not the cause of a large deviation in water consumption. The promptly generated alarm triggered a rapid deployment of the municipal water workers. On site, they were surprised to discover that the neighbor had used the daycare center's outdoor tap to fill his pool over the weekend.

The SWAN Gateway from WEPTECH therefore offers outstanding functionality and benefits, especially in conjunction with the implemented alarm message.