Modbus
Modbus is a master-slave communications protocol typically used for industrial applications.
Modbus/TCP
Modbus/TCP is an open standard protocol very similar to Modbus RTU except that it uses standard
Internet communication protocols.
MultiHop
MultiHop networks are made up of one master radio and many repeater and slave radios. The MultiHop
networks are self-forming and self-healing networks constructed around a parent-child communication
relationship. A MultiHop Radio is either a master radio, a repeater radio, or a slave radio.
The master radio controls the overall timing of the network and is always the parent device for other
MultiHop radios. The host system connects to this master radio. Repeater radios extend the range of
the wireless network and slave radios are the end point of the wireless network.
For more information, refer to the
Sure Cross MultiHop Radios Instruction Manual
).
multipath fade
Obstructions in the radio path reflect or scatter the transmitted signal, causing multiple copies of a
signal to reach the receiver through different paths. Multipath fade is the signal degradation caused by
these obstructions.
network ID
The Network ID (NID) is a unique identifier you assign to each wireless network to minimizes the
chances of two collocated networks interfering with each other. Assigning different NIDs to different
networks improves collocation performance in dense installations.
node
A node is any communications point within a network.
Node
Nodes are remote I/O slave devices within Banner's wireless sensor networks. Sensors and other
devices connect to the Node's inputs or outputs, allowing the Node to collect sensor data and
wirelessly transmit it to the Gateway. Every Sure Cross device is a transceiver, meaning it can transmit
and receive data.
noise
Noise is any unwanted electromagnetic disturbances from within the RF equipment, especially the
receiver. Noise is more of a concern when signal levels are low.
omni-directional
antenna
Omni-directional antennas transmit and receive radio signals equally in all directions.
out of sync/link
loss (loss of
radio signal)
The Sure Cross wireless devices use a deterministic link time-out method to address RF link interruption
or failure. When a radio link fails, all pertinent wired outputs are sent to the selected default value/state
until the link is recovered, ensuring that disruptions in the communications link result in predictable
system behavior. Following a time-out, all outputs linked to the Node in question are set to 0, 1, or hold
the last stable state depending on the value selected.
path loss
Path loss describes attenuation as a function of the wavelength of the operating frequency and the
distance between the transmitter and receiver.
path loss (or link
loss)
calculations
Link loss calculations determine the capabilities of a radio system by calculating the total gain or loss for
a system. If the total gain/loss is within a specific range, the radio signal will be received by the radio.
Total Gain = Effective Free space loss + Total received power . Because the transmitter and
receiver gains are positive numbers and the free space loss is a larger negative number, the total gain of
a system should be negative. A link loss calculation may also be called a link budget calculation.
peer to peer
network
Peer-to-peer is a model for a communication protocol in which any device in the network can send or
receive data. Any device can act as a Master to initiate communication.
polling interval/
rate
The Gateway communicates with, or polls, each Node to determine if the radio link is active. The polling
rate defines how often the Gateway communicates with each Node. Polling is always initiated by the
Gateway and only verifies radio signal communications.
Are you there?
Yes, I am here.
polling interval/
rate and
maximum
misses
The Gateway communicates with, or polls, each Node to determine if the radio link is active. The polling
rate, or interval, defines how often the Gateway communicates with each Node. Polling is always
initiated by the Gateway and only verifies radio signal communications. Nodes that fail to respond are
counted against the ‘Maximum Misses’ for that Node. If the ‘Maximum Misses’ is exceeded for any
Sure Cross
®
Performance DX80 Wireless I/O Networks
www.bannerengineering.com - Tel: + 1 888 373 6767
63
