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Introduction into the RF System of the RMS


  • Introduction into the RF System of the RMS

    Introduction RMS RF System
    Click image for larger version  Name:	RF network.png Views:	0 Size:	497.8 KB ID:	549

    The Gateway and the RF Logger are organized in a RF network of tree structure.
    At this RF Infrastructure, the Gateway represents the interface between the RF Logger and the RMS.
    For every linked RF Logger, the gateway organizes
    • common and repetitive communication (e. g. measurement data, time stamp, device ID etc.)
    • extraordinary communication (e. g. FW update)
    • time synchronization of each RF logger for a correct time stamp for each measurement value.
    In communication to the RMS, the gateway works as an IOT device and sends its information, data etc. from itself to the RMS server.

    • RMS-GW-898/915 (Gateway) – Interface RF Logger to RMS.
    • RMS-LOG-868 / RMS-LOG-915 – RF Transmitter and Logger for the use of digital probes as HCD (humidity / temperature), PCD (differential pressure) and CCD (CO2 concentration)
    • RMS-MLOG-xxx – RF devices with transmitting and logger function for different parameters (temp., humidity, ADC, digital-Input, light, barometric pressure)
    • RMS-LOG-T30-868/915 - RF Transmitter and Logger for temperature measurement using PT100 sensors.

    RF Management

    • 868MHz (Europe)
    • 915 MHz (North America)
    If you like to use RF devices in another region, please consider the national regulations regarding the use of frequencies.

    RF Channels

    For both frequencies there are different quantities of available channels. That is related to the requirements of the national RF regulations of the use of frequencies.
    • 5 Channels for common operation
    • 1 Service channel for special features that requires an extraordinary communication as e. g. FW update.

    • 10 Channels for common operation
    • 1 Service channel for special features that requires an extraordinary communication as e. g. FW update.

    Each gateway is configured and supplies only one channel (for common operation).
    For extraordinary communication, the gateway interrupts the common operation, changes to a service channel and executes special requests as e. g. FW update. During the interruption, the other logger does not communicate with the gateway but log the data. After the change back to the common operation, the logged data will be transferred to fulfill the data gap.


    Each gateway can communicate with max. 60 RF logger. Each RF logger receives its own address between 1 and 60 during the pairing procedure.
    The communication is organized in that way, that the gateway communicates with every single RF logger in sequence every second of an interval. The max. number of RF logger per channel / gateway is 60.
    A higher interval doesn’t increase the max. number of 60 RF Logger.
    A lower interval of e. g. 10sec. (only with RMS web server possible, not with RMS Cloud) reduces the max. number of RF logger per channel/gateway. Because e. g. a device paired with 10 seconds on address 1, occupies also the addresses 11, 21, 31, 41, 51. At this example only max. 10 RF logger can be paired per channel/gateway.

    Net IDs

    If all channels are already occupied with gateways and RF logger (300 RF logger within an 868MHz), the number of RF logger can still be increased within a RMS company. For that reason, every gateway receives its own Net ID.
    E. g. two gateways, both configured to use the same channel must have a different Net ID (e. g. 1 and 6) to be able to communicate with max. 60 RF logger each gateway. But beware! These gateways must be placed in a certain distance (e. g. in different buildings) to avoid RF disturbance.

    To increase the communication stability within a RF channel, it is possible to install more than one gateway with the same channel within the RF range. By this way the number of access points per channel is increased. The RF logger communicated automatically with the gateway of the strongest field strength (RSSI). For that special case, the Net ID must be the same for every gateway (access point).

    Time synchronization

    Every RF logger must be time synchronized to link the measured and logged data to the correct time stamp. The time synchronization runs in this manner: UTC time server -> RMS server -> gateway -> RF logger. The synchronization happens every interval.

    Paring procedure

    Paring Gateway:
    • Please click Tools à Setup à Devices à New à LAN device …
    • Define Channel and Network ID
    • Address is fix – 254

    Paring RF logger:
    • Please click Tools à Setup à Devices à New à wireless device …
    • Define Channel and address. Beware! The use of channels and addresses must be managed manually (lists, tables etc.) to keep the overview of all used channels and addresses.

    FW Update of RF logger

    FW update of the RF logger can be done within the RMS. Please consider the Online Manual for the actual versions.

    RMS Cloud:
    The newest FW files are available everytime.
    FW update: Please click Tools -> Setup -> Devices -> Options -> Firmware update…

    RMS Web Server:
    Please check for new FW files available at
    Import of FW file: Please click Tools -> Setup -> Devices -> Options -> Import firmware file…
    FW update: Please click Tools -> Setup -> Devices -> Options -> Firmware update…

    Guidline and Recommendation for setting up a RF network

    Network structure
    • Use a unique network ID for each gateway (or gateways if redundancy is established) on a channel.
    • Install multiple gateways on the same channel to create redundancy and improve coverage.
    • Use a separate channel for each floor in a building.
    • Large local separation of networks with adjacent channel numbers.
    • Considering networks in adjacent buildings during planning.
    • Maintaining a distance of at least 3 floors if a channel is used for several networks in the same building.
    • Maintain a distance of at least 2 floors if a channel that has already been used is used again in adjacent buildings.
    • Separate the networks first via channels, then via addresses. Then via network IDs, but only if it is ensured that no interference is generated on the channel.
    Channel seperation

    Five channels for 868MHz and 10 channels for 915MHz are available in the system. Basically these are separated from each other in the radio spectrum, but this separation is not strict. If radio networks are operated in the immediate vicinity on adjacent radio channels, the reliability of reception may deteriorate.
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