What is the definition of "transmission medium"?
The means by which data travels through a network. Typically this is some type of cable, although wireless networks are becoming increasingly common.

Learn more about transmission medium in the class Networking for PLCs 270 below.


PLCs Training


Class Information
Tooling U-SME classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:Networking for PLCs 270
Description:This class covers the basic principles of PLC networking and provides an introduction to some common industrial networks. Includes an Interactive Lab.
Prerequisites: none
Difficulty:Intermediate
Number of Lessons:15
Language:English, Spanish
 
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Class Outline
  • Objectives
  • What Is a Network?
  • Network Topology
  • Network Transmission Media
  • Wireless Networks
  • Ethernet Networks
  • Ethernet Communication Protocol
  • Ethernet Network Access
  • Industrial Networks
  • Gateways
  • Repeaters and Hubs
  • Switches and Bridges
  • Routers and Firewalls
  • Industry Trends in PLC Networking
  • Summary
  
Class Objectives
  • Define a network.
  • Differentiate between network topologies.
  • Differentiate between types of network cable.
  • Describe how wireless networks work.
  • Describe Ethernet networks.
  • Explain how Ethernet communication protocols work.
  • Describe how Ethernet network access works.
  • Identify common industrial networks.
  • Describe network gateways.
  • Distinguish between repeaters and hubs.
  • Distinguish between switches and bridges.
  • Describe network routers and firewalls.
  • Describe upcoming industry trends in PLC networking.

Class Vocabulary

Vocabulary TermDefinition
1000Base Ethernet cable with a bandwidth of 1,000 Mbps. Also known as gigabit cable.
100Base Ethernet cable with a bandwidth of 100 Mbps. Also known as fast Ethernet cable.
10Base Ethernet cable with a bandwidth of 10 Mbps.
adapter A part that allows a device to be electrically or physically connected to another device. Network interface cards can be used as adaptors for network cables.
antenna An apparatus for sending and receiving radio signals. Wireless routers have an antenna instead of cable.
backbone The main line of a communications network that supports all the data being transmitted.
bandwidth The amount of information or data that can be sent over a communications channel in a given period of time. The higher a channel's bandwidth, the more information it can carry.
boundary The separation point between network segments. Boundaries are usually set by devices that control the data, such as routers and gateways.
bridge A hardware device that connect two networks and breaks the segments of one network into smaller groups. Bridges filter incoming traffic and decide whether to forward or discard it.
bus A network configuration in which all the nodes are connected to a common line with two endpoints. Bus topology is easy to connect and does not require a lot of cable.
carrier sense The ability of a network device to "listen" to the network to determine if any other devices are trying to transmit data.
carrier sensing multiple access with collision detection An Ethernet communication protocol in which devices check the network to see if it is clear before transmitting data.
CAT 5 A type of communications cable used for high rates of data transmission.
coaxial cable A type of communications cable used in heavy industry. Coaxial cable has the highest resistance to noise of all copper cables.
collision A situation in which two or more network devices send data at the same time.
collision detection The ability of network nodes to sense when there is a collision. When collisions occur, the nodes simply wait to re-transmit the information
configurable gateway A hardware device that allows you to select which competing technologies you wish to connect. Configurable gateways contain many different hardware and communications protocols.
configuration table Information contained within a network router on the location of network devices and the pathways to those devices.
contention-based A method of network access used by Ethernet to control communications flow. Devices on the network compete with each other for network access.
controller area network An industrial network designed specifically for noisy environments. Also known as CAN.
CSMA/CD An Ethernet communication protocol in which devices check the network to see if it is clear before transmitting.
data Information is transmitted or processed digitally. In data transmission, a "1" or "0" represents the most fundamental unit of information in a digital system.
DeviceNet A protocol created by Allen-Bradley that operates on a controller area network (CAN) infrastructure.
dielectric material The insulating non-metallic material that separates conductors and the outer protective covering.
distributive control A method of control that divides remote I/Os and control devices among multiple PLCs instead of using a single PLC to control all the devices.
electrical noise An AC power line disturbance caused by sudden changes in the load. Electrical noise is problematic to PLCs and data communications equipment because they cannot differentiate between an intended electrical pulse and an unintended electrical spike.
electromagnetic interference Electrical noise in a circuit that can interrupt or degrade the performance of the circuit. Fiber optic cables are resistant to electromagnetic interference.
Ethernet The oldest computer network. Ethernet is considered the industry standard for local area networks.
fast Ethernet cable Cable with a bandwidth of 100 Mbps. Also known as 100Base cable.
fiber optic cable A cable packed with thin, flexible glass or plastic optical fibers that transmit light instead of electricity.
fieldbus A type of industrial network that uses distributive control instead of relying on a central controller.
firewall A piece of hardware or software that protects a network from unwanted content or unauthorized users.
Foundation Fieldbus A fieldbus protocol created by a not-for-profit trade group. Foundation Fieldbus is designed to be compatible with other networks.
gateway A device used to join different hardware or protocols on a network and make them compatible.
gigabit cable Cable with a bandwidth of 1,000 Mbps. Also known as 1000Base cable.
hacking The access and use of a network by unauthorized persons or devices. Hacking typically comes from outside the network.
header A data field within a packet that includes the IP addresses of the sender and the receiver.
hub A network hardware device that provides a central connection point for all the nodes on a network.
IEEE 802.3 A set of IEEE standards for network transmission media.
industrial Ethernet Ethernet cables that are made to withstand harsh industrial environments.
industry standard A universally accepted set of guidelines for the operational quality of a device or process.
infrastructure The physical equipment that makes up the network. The most important part of PLC network infrastructure is the transmission medium.
input/output device A device connected to the input/output section of a PLC. Inputs are usually sensors while outputs are usually devices that perform a mechanical action.
interface A hardware device that connects two separate pieces of equipment. RS-232 cable can be used as an interface between computers and printers.
IP address A unique numeric identifier for each node on a network. An IP address is comparable to the mailing address of your home.
jacket The protective outer layer surrounding coaxial cable. The jacket protects the cable from physical damage.
kilobit One thousand bits. A bit is a single numerical unit in the binary number system.
local area network A small data communications network that is usually confined to a single room or building.
megabit One million bits. A bit is a single numerical unit in the binary number system.
message The instructions contained in a data packet.
microsecond One trillionth of a second.
Modbus A communication protocol created by Modicon to be compatible with a variety of other networks. Modbus uses an older type of interface called RS-232.
multiple access A type of network access in which each node on the network has the same right to transmit data packets as any other node.
network Two or more linked devices that use a set of rules or a set of protocols to communicate with each other. PLC networks are often used to control remote I/Os.
network interface card A printed circuit board inside a device that provides a network address for the device. The NIC also acts as an adapter for the network transmission media and interprets transmission protocols.
NIC Network Interface card. A printed circuit board inside a device that provides a network address for the device.
node A device or group of devices on a network that possesses an address.
packet A unit of data that carries information such as instructions. TCP/IP is a communications protocol that breaks data up into packets.
PLC Programmable logic controller. A processor driven device that uses logic based software to provide electrical control to machines.
printed circuit board A layered construction of material used to mechanically support and electrically connect electronic components using conductive pathways, or traces, etched from copper sheets laminated onto a non-conductive surface.
Profibus A fieldbus protocol created by PI International. Profibus is widely used in industry.
programmable logic controller A processor driven device that uses logic based software to provide electrical control to machines. Also known as a PLC.
protocol The standards and rules used by PLCs and other network devices to interact with each other. In many respects, protocols are the language that network devices use to communicate.
radio wave A wave on the electromagnetic spectrum that is used for communication.
remote I/O An input/output module that is located far away from the CPU of the PLC.
repeater A hardware device that amplifies a signal that has traveled a long distance.
ring A network topology that connects the nodes in a closed loop. Ring topologies are very orderly, with each device on the network performing an equal amount of work.
router A network device that determines where information packets should go and sends them to their destination by the shortest, most efficient route.
RS-232 An older type of communications cable that was used for connecting peripheral devices to a computer.
segment A section of a network in which all the nodes use the same cable. Hardware devices that create or extend the connection, like hubs, switches, and bridges, are also considered part of that segment.
shield An inner protective covering on a wire or cable.
shielded twisted pair Shielded cable that is made of pairs of copper wires that are twisted around each other. Shielded twisted pair has more immunity to electrical noise than unshielded twisted pair.
spam SPecialized Automated Mail. Spam is electronic junk mail.
star A network topology in which each node on the network is connected to a central controller. In a star configuration, the controller takes an active role in analyzing and transmitting data packets while the nodes passively receive the information.
switch A network hardware device that allows different nodes on the network to communicate with each other. Switches have the ability to selectively forward data packets to a specific destination.
TCP/IP A communications protocol used by Ethernet that breaks up data into small packets.
thick coaxial cable Coaxial cable with a diameter of .393 inches (1 cm). Also known as thicknet.
topology The configuration of network cable and devices.
transmission control protocol/internet protocol A communication protocol used by Ethernet that breaks data up into small packets.
transmission medium The means by which data travels through a network. Typically this is some type of cable, although wireless networks are becoming increasingly common.
trunk The common line of a bus network that supports all the data being transmitted.
twisted pair cable Cable made of pairs of copper wires that are twisted around each other. Twisted pair is relatively inexpensive and can be found in most buildings
unshielded twisted pair Cable made of pairs of copper wires that are twisted around each other.
wireless network A network that uses radio waves instead of copper or fiber optic cable. In a wireless network, a device transmits a radio signal through an antenna.
wireless router A router that transmits data through an antenna rather than a network cable. Wireless routers use radio waves.
Xerox Corporation A manufacturer of photographic paper and equipment that developed Ethernet.