Banner SureCross DX80 Wireless Networks - Manual (Page 3)

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Banner Engineering Corp. • Minneapolis, MN U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
Networking
Networks exist everywhere around us and are a major contributor to the information age . Some of the most interesting recent
developments in factory and process automation have been the networking of machines and controls allowing machine control, data
collection, and ultimately informed decisions that can improve productivity, save time, and reduce scrap.
According to Merriam-Webster Online, a network is “a system of computers, peripherals, terminals, and databases connected by [a]
communications line .” Today’s implementations of networks also include wireless networks that use the air as the communications line
and range in geographic size from a few meters to spanning continents .
Many of Banner’s newest products are part of a network, both wired and wireless. As such, understanding networking basics is
important when using or providing technical support to Banner’s products .
Network Topologies
There are many network topologies, or arrangements, and each topology contributes to the overall network performance. Defined here
are a few of the most common topologies for basic networks. In reality, many networks combine elements from multiple topologies.
Point to Point: The most basic form of network is called a point-to-point, or line, network. Data typically
travels from one node to the next in a specific order. If the communications link between two nodes fails, the
network communication halts .
Bus: In a bus network, the nodes are connected through a common communication path, called a bus. Each node
on the bus is assigned a unique ID to receive the messages intended for it . All data is transmitted and received
by all nodes connected to the bus, though only the intended target responds. Similar to the line network, all
communication relies on one common cable connection, so a failure in the bus halts all network operation.
Ring: A ring topology is similar to a bus except that the common cable is looped into a continuous ring . Data is
transmitted in one direction and if the link is lost, network communication fails. Because the data travels in a single
direction and in a specific order, adding nodes to the ring increases the total network response time.
Tree: At the lowest level are nodes, referred to as leaves. Their only function is to transmit information to the
next highest level . The mid-level devices are repeaters and at the top is the gateway . While the tree topology
handles additional nodes better than the ring or bus topology, if a repeater fails, the connection between the
nodes and their gateway is lost .
Mesh: In a mesh network, each node has limited routing capabilities and maintains a network connection with
at least two other nodes. Most commonly, nodes within a mesh network maintain a link with all nodes within a
specified distance. If one link breaks, information has an alternative path to the gateway. The gateway in this case
could be any one node in the network . Mesh networks are reliable because of the greater redundancy in data
transmission pathways, but performance slows with each node added to the system.
Star: When many devices are connected to a single point—for example when a number of nodes connect to a single
gateway—it’s called multi-point to point. Because of its shape, this network is also referred to as a hub and spoke
network, or a star network.
Star topologies also can suffer from some speed decreases with each additional node, but when one node fails, the
others remain unaffected . Because the star topology balances performance and speed and allows the use of specific
transmit and receive timing, Banner’s SureCross wireless network products use the star topology for the wireless
networks .