GL.3
Date Code 20090730 Instruction Manual SEL-734 Meter
Glossary
Conditioning Timers—Dial
Conditioning Timers
Timers for conditioning Boolean values. Conditioning timers either stretch
incoming pulses or allow you to require that an input take a state for a certain
period before reacting to the new state.
Contact Input
See Control input.
Contact Output
See Control output.
Control Input
Meter inputs for monitoring the state of external circuits. Connect auxiliary
meter and circuit breaker contacts to the control inputs.
Control Output
Meter outputs that affect the state of other equipment. Connect control outputs
and SCADA systems.
Counter
Variable or device such as a register or storage location that either records or
represents the number of times an event occurs.
CT
Current transformer.
CTR
Current transformer ratio.
Data Bit
A single unit of information that can assume a value of either logical 0 or
logical 1 and can convey control, address, information, or frame check
sequence data.
Data Label
The identifier for a particular data item.
Data Objects
Individual pieces of UCA data created from instances of common class
components or data items that are instances of standard data types.
DCE Devices
Data communication equipment devices (modems).
Deadband
The range of variation an analog quantity can traverse before causing a
response.
Deassert
To deactivate. To remove the logic or electrical requirements needed to
operate a device. To clear a logic condition to its false state (logical 0). To
open the circuit or open the contacts across an SEL-734 input. To open a
normally open output contact. To close a normally closed output contact.
Debounce Time
The time that masks the period when meter contacts continue to move after
closing; debounce time covers this indeterminate state.
Default Data Map
The default map of objects and indices that the SEL-734 uses in DNP
protocol.
Delta
A phase-to-phase series connection of circuit elements, particularly voltage
transformers or loads.
Demand Meter
A measuring function that calculates a rolling average, block, or thermal
average, block, of instantaneous measurements over time.
Dial
The clock-type hands on an electromechanical register. The “number of dials”
on the meter must be known to the billing system in order to properly detect a
rollover condition. Four- and five-dial registers are commonly used.
Courtesy of NationalSwitchgear.com
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