1st Fresnel Zone
2nd Fresnel Zone
3rd Fresnel Zone
Tx
Rx
gain
Gain represents how well the antenna focuses the signal power. A 3 dB gain increase doubles the
effective transmitting power while every 6 dB increase doubles the distance the signal travels.
Increasing the gain sacrifices the vertical height of the signal for horizontal distance increases. The
signal is ‘squashed’ down to concentrate the signal strength along the horizontal plane.
gateway
A gateway is a general network device that connects two different networks.
Gateway
A Sure Cross
®
Gateway is the wireless sensor network master device used to control network timing
and schedule communication traffic. Similar to how a gateway device on a wired network acts as a
"portal" between networks, the Sure Cross Gateway acts as the portal between the wireless network
and the central control process. Every wireless I/O sensor network requires one Gateway device. Every
Sure Cross device is a transceiver, meaning it can transmit and receive data.
GatewayPro
The GatewayPro combines the standard Gateway and the DX83 Ethernet Bridge into one device.
ground loop
Ground loops are grounds within a system that are not at the same potential. Ground loops can damage
electrical systems.
ground plane
A ground plane is an electrically conductive plate that acts as a ‘mirror’ for the antenna, effectively
doubling the length of the antenna. When using a 1/4 wave antenna, the ground plane acts to ‘double’
the antenna length to a 1/2 wave antenna.
heartbeat mode In heartbeat mode, the Nodes send "heartbeat" messages to the Gateway at specific intervals to
indicate the radio link is active. The heartbeat is always initiated by the Node and is used only to verify
radio communications. Using the Nodes to notify the Gateway that the radio link is active instead of
having the Gateway "poll" the Nodes saves energy and increases battery life.
I am here
hibernation/
storage mode
While in storage mode, the radio does not operate. All Sure Cross
®
radios powered from an integrated
battery ship from the factory in storage mode to conserve the battery. To wake the device, press and
hold button 1 for 5 seconds. To put any
Flex
Power
®
or integrated battery Sure Cross radio into storage
mode, press and hold button 1 for 5 seconds. The radio is in storage mode when the LEDs stop
blinking, but in some models, the LCD remains on for an additional minute after the radio enters storage
mode. After a device has entered storage mode, you must wait 1 minute before waking it.
For the Wireless Q45 and Q120 Sensors: While in storage mode, the Gateway or Node's radio does not
operate. The Gateway or Node ships from the factory in storage mode to conserve the battery. To wake
the device, press and hold the binding button (inside the housing on the radio board) for five seconds.
To put any Gateway or Node into storage mode, press and hold the binding button for five seconds. The
Gateway or Node is in storage mode when the LEDs stop blinking.
hop
As a verb, hopping is the act of changing from one frequency to another. As a noun, a hop is the device
to device transmission link, such as from the Master device to the Slave device.
hop table
A hop table is a precalculated, pseudo-random list of frequencies used by both the transmitter and
receiver of a radio to create a hopping sequence.
hysteresis
Hysteresis defines how far below the active threshold (ON point) an analog input is required to be before
the input is considered OFF. A typical hysteresis value is 10% to 20% of the unit’s range. For more
specific details, see
Threshold
.
Sure Cross
®
Performance DX80 Wireless I/O Networks
www.bannerengineering.com - Tel: + 1 888 373 6767
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