GL.2
SEL-734 Meter Instruction Manual Date Code 20090730
Glossary
ASCII Terminal—Comparison
ASCII Terminal
A terminal without built-in logic or local processing capability that can only
send and receive information.
Assert
To activate. To fulfill the logic or electrical requirements needed to operate a
device. To set a logic condition to the true state (logical 1) of that condition.
To apply a closed contact to an SEL-734 input. To close a normally open
output contact. To open a normally closed output contact.
AT Modem Command Set
Dialing String Standard
The command language standard that Hayes Microcomputer Products, Inc.
developed to control auto-dial modems from an ASCII terminal (usually
EIA-232 connected) or a PC (personal computer) containing software
allowing emulation of such a terminal.
Automatic Messages
Messages including status failure and status warning messages that the meter
generates at the serial ports and displays automatically on the front-panel
LCD.
Bandpass Filter
A filter that passes frequencies within a certain range and blocks all
frequencies outside this range.
Bit Label
The identifier for a particular bit.
Bit Value
Logical 0 or logical 1.
Blondel’s Theorem
This theorem states that in a system of N conductors, N-1 meter elements,
properly connected, will measure the power or energy taken. The connection
must be such that all voltage coils have a common tie to the conductor in
which there is no current coil.
Boolean Logic Statements
Statements consisting of variables that behave according to Boolean logic
operators such as AND, NOT, and OR.
Checksum
A method for checking the accuracy of data transmission involving
summation of a group of digits and comparison of this sum to a previously
calculated value.
CID
Checksum identification of the firmware.
Class Designation
The maximum of the watt-hour meter load range in amperes. This value is
indicated on the faceplate after the abbreviation CL. Typical class designations
for transformer-rated meters are CL 10 or CL 20. A typical class designation
for a residential type meter is CL 200.
Cold Start
Beginning a system from power up without carryover of previous system
activities.
Commissioning Testing
Testing that serves to validate all system ac and dc connections and confirm
that the meter, auxiliary equipment, and SCADA interface all function as
intended with your settings. Perform such testing when installing a new
metering system.
Common Inputs
Meter control inputs that share a common terminal.
Communications Protocol
A language for communication between devices.
Comparison
Boolean SELOGIC control equation operation that compares two numerical
values. Compares floating-point values such as currents, total counts, and
other measured and calculated quantities.
Courtesy of NationalSwitchgear.com
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