Comark RF500A - Manual (Page 38)

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Meshing Transmitters and Backbone Transmitters
Whenever a RF512, RF513 or RF516 transmitter is powered by a RF520 AC adaptor it will become a Meshing
transmitter and will form part of the radio mesh network, intelligently forwarding messages on behalf of other
transmitters. However if external power is removed it will revert back to a regular transmitter.
In “Figure 18 - A Typical Mesh Network” above , regular Transmitter B is supported by its nearest Mesh Transmitter
(coloured blue/dark) which in turn is supported by other Mesh Transmitters. If external power failed on one on those
Mesh Transmitters; Transmitter B would not have a route back to the Gateway, effectively isolating it from the radio
network. To prevent missed alerts from transmitters such as B it is recommended to set those Mesh Transmitters it
depends on for its radio route to the Gateway as Backbone Transmitters.
RF512, RF513 and RF516 have the option to become “Network Backbone” transmitters, this option can be enabled
using a setup option in the Gateway. Backbone transmitters will form part of the mesh network continuously even
when not powered by a RF520. Due to the very large drain on the internal battery, Backbone transmitters must be
powered using a RF520 mains adaptor. The internal battery is considered only as a backup battery for Backbone
transmitters.
Automatic Data Retrieval (ADR)
The fact that transmissions between transmitters and the RF500 Gateway are acknowledged ensures that the
transmitters know exactly which data records have been successfully transferred to the Gateway and those which
must be re-transmitted. Therefore if the Gateway is temporarily unable to receive or transmit messages for whatever
reason, data will not be lost during this period. When the Gateway is again able to receive and transmit properly the
transmitters will re-transmit those records which were unable to be transmitted during the period of outage.
This re-transmission of data happens automatically without user intervention and results in seamless graphical and
tabular data with no gaps.