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Glossary

Actuator Mechanism of the switch or switch enclosure which operates the contacts.
Baud A measure of communication speed. Defined as bit/second.
Bit A single unit of memory (i.e., 0 or 1). See Byte.
Byte A unit of memory storing 8 adjacent bits, and defining one alphanumeric character.
Control Editor The software that organizes and controls the network. This may be a Windows based program, and can use flowchart code, ladder logic, or any other control language.
Controller Area Network (CAN) A communications protocol specification that defines: (1) A media access control methodology, and (2) Physical signaling. CAN is a broadcast-oriented protocol. CAN frames transmitted on the network are assigned an identifier, and each station decides, based on this identifier, whether or not it receives the frame.
Dropline Cable attaching a device to the trunk cable of a DeviceNet system. Must be a thin cable.
Dynamic Data Exchange (DDE) A communication protocol that allows different software to packages to pass information back and forth.
Electrical Noise Noise results from the presence of undesirable electrical voltages or current. It causes devices to operate erratically (if the noise is on the supply line to a device), or produces false information or erratic operation (if present on wires carrying signals from the output of a device to the load). Noise can be present in the supply or picked up on lines in many ways. Pick-up from noisy adjacent wires or metal parts is possible. Good wiring practice and/or additional parts can be used to diminish the effects of noise.
Human Machine Interface (HMI) Software package that uses a graphical interface to allow an operator to control a machine or operation.
Industrial Personal Computer (iPC) Computer specifically designed to handle harsh environments but still give all the features of a standard PC.
Intelligent Device Device that is able to transmit a higher level of information about its condition (i.e., diagnostics), and react to received information in an advanced manner (i.e., change via network command).
Limit Switch Contact sensors used for detecting the presence or position of objects.
Media Access Control Identifier (MAC ID) An integer identification value assigned to each node on DeviceNet. This is commonly referred to as either a device MAC ID or Node Address. No two devices on a network may have the same MAC ID assigned to them.
NEC National Electrical Code.
NEMA National Electrical Manufacturers Association.
Node A junction, or a collection point, on a network. It may refer to a single device, i.e., a particular limit switch. A node could also be a group of devices wired to a terminal block of inputs and outputs—a block I/O.
ODVA Open DeviceNet Vendor Association. ODVA is an independent association made up of hardware and software vendors, and customers, whose purpose is to develop and foster standards for devices, software, and a network for byte level (machine control) communications.
Off Delay Logic Adjustable delay (after input signal stops) before output is de-energized.
On Delay Logic Adjustable delay (after onset of input signal) before output is energized.
Open Architecture Refers to the ability of any vendor to produce products that can communicate freely on a published standard.
Photoelectric Sensor Non-contact sensor used for detecting the presence or absence of objects. It is turned on or off by the presence or absence of received light.
Programmable Logic Controller (PLC) The PLC is the dominant tool for plant-floor control, monitoring, and sequencing of events involving input devices and output devices. Built around a microprocessor, it is designed specifically for control.
Proximity Sensor A sensor with the ability to detect the presence of a metal-only target, within a specified range, and without making physical contact.
Relay Circuits Devices often used in control. Can be opened and closed electronically to complete logic circuits.
Sensor A sensing element. The basic element that usually changes some physical parameter to an electrical signal.
Special Interest Group Special Interest Groups (SIGs) are formed by two or more members with a common interest or product line, for the purpose of setting and advancing standards. The Open DeviceNet Vendor Association offers numerous SIGs to join.
Standard Device Device on a network that does not convey advanced information about its status over the network, or react to a received command in an advanced manner. In general terms, other than On/Off, standard devices must be inspected manually and have their status changed manually.
Starter A control device usually consisting of a contact and overload. With DeviceNet, it will also contain a communication module used for starting and stopping loads.
Trunk Line The main line of communication for a DeviceNet system. It can be either thick or thin cable.
UL-Underwriter's Laboratories, Inc. A non-profit organization that establishes, maintains and operates laboratories for the examination and testing of devices, systems and materials, primarily for safety.

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