Glossary Of Terms - Leroy-Somer digitax st User Manual

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Glossary of terms

Address: This is the unique network identification given to a networked device to allow
communication on a network. When a device sends or receives data the address is
used to determine the source and the destination of the message.
Bit: A binary digit, this may have the value of 1 or 0.
Block mapping: A method of mapping a range of consecutive parameters using only
two ascending parameters. This means that by using two mapping parameters up to 32
consecutive mappings may be made. See section 12.6 Block mapping on page 76 for
more information.
Byte: A collection of eight binary digits that collectively store a value. This may be
signed or unsigned.
Casting: The process of changing between data sizes without changing the value
represented, e.g. changing from 16-bit to 32-bit.
Compression: By default SM-PROFIBUS DP-V1 transmits values as 32-bits on the
network. It is possible by using data compression to reduce the number of bits
transmitted when sending 16-bit (or smaller) values on the network to 16-bit (32-bit
values will still be transmitted as 32-bit values). This has the advantage of reducing the
volume of traffic on the network and allowing more parameters to be mapped within the
SM-PROFIBUS DP-V1.
Consistency: Describes how data is transmitted between nodes on the network. If data
is consistent it is transmitted from node to node as a single entity. Thus preventing data
corruption where multiple bytes are transmitted or received individually.
Control word: A collection of binary digits that are used to control the drive. Features
typically include directional controls, run controls and other similar functions.
CT Single Word non-cyclic: see Mode 1 non-cyclic in this section.
Cyclic channel: An area of the Profibus-DP message frame used for cyclic
communication to a single drive parameter.
Cyclic data: This consists of values that are sent at regular or cyclic intervals across the
network. A typical use of cyclic data would be the transmission of a speed reference or a
control word.
Data format: Determines the quantity and function of the network data.
Data rate: Determines the communication speed of the network, the higher the value
the more data can be sent across the network in the same time period.
Device: A piece of equipment connected to a network, this may be any type of
equipment including repeaters, hubs, masters or slaves.
SM-PROFIBUS DP-V1 User Guide
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